Wednesday, December 21, 2011

Polycystic ovarian syndrome

Polycystic ovarian syndrome :

     Polycystic ovarian disease ,  is a hormonal problem that causes women to have a variety of symptoms. It should be noted that most women with the condition have a number of small cysts in the ovaries. However, women may have cysts in the ovaries for a number of reasons, and it is the characteristic constellation of symptoms, rather than the presence of the cysts themselves, that is important in establishing the diagnosis of PCOS. PCOS occurs in 5% to 10% of women and is the most common cause of infertility in women.

 Symptoms of polycystic ovarian syndrome :

    The main signs and symptoms of PCOS are related to menstrual irregulatories and elevated levels of male hormones (androgens). Menstrual irregulatories can include delay of normal menstruation (primary amenorrhea), the presence of fewer than normal menstrual periods (oligomenorrhea), or the absence of menstruation for more than three months (secondary amenorrhea). Menstrual cycles may not be associated with ovulation (anovulatory cycles) and may result in heavy bleeding. Symptoms related to elevated androgen levels include acne, excess hair growth on the body (hirsutism), and male-pattern hair loss.
Other signs and symptoms:
    Obesity, weight gain, increase insuline level, oily skin, dandruff, infertility, high cholesterol levels.

 Causes polycystic ovarian syndrome:

      No one is quite sure what causes PCOS, and it is likely to be the result of a number of both genetic (inherited) as well as environmental factors. Women with PCOS often have a mother or sister with the condition, and researchers are examining the role that genetics or gene mutations might play in its development. The ovaries of women with PCOS frequently contain a number of small cysts, hence the name poly=many cystic ovarian syndrome. A similar number of cysts may occur in women without PCOS. Therefore, the cysts themselves do not seem to be the cause of the problem.  A malfunction of the body's blood sugar control system (insulin system) is frequent in women with PCOS, who often have insulin resistance and elevated blood insulin levels, and researchers believe that these abnormalities may be related to the development of PCOS. It is also known that the ovaries of women with PCOS produce excess amounts of male hormones known as androgens. This excessive production of male hormones may be a result of or related to the abnormalities in insulin production.  Other possible contributing factors in the development of PCOS may include a low level of chronic inflammation in the body and fetal exposure to male hormones.

 Diagnosis

      The diagnosis of PCOS is generally made on the basis of clinical signs and symptoms as discussed above. The doctor will want to exclude other illnesses that have similar features, such as low thyroid hormone blood levels (hypothyroidism) or elevated levels of a milk-producing hormone (prolactin). Also, tumors of the ovary or adrenal glands can produce elevated male hormone (androgen) blood levels that cause acne or excess hair growth, mimicking symptoms of PCOS.  Other laboratory tests can be helpful in making the diagnosis of PCOS. Serum levels of male hormones (DHEA and testosterone) may be elevated. However, levels of testosterone that are highly elevated are not unusual with PCOS and call for additional evaluation. Additionally, levels of a hormone released by the pituitary gland in the brain (LH) that is involved in ovarian hormone production are elevated.  The cysts (fluid filled sacs) in the ovaries can be identified with imaging technology. (However, as noted above, women without PCOS can have many cysts as well.) Ultrasound, which passes sound waves through the body to create a picture of the kidneys, is used most often to look for cysts in the ovaries. Ultrasound imaging employs no injected dyes or radiation and is safe for all patients including pregnant women. It can also detect cysts in the kidneys of a fetus. Because women without PCOS can have ovarian cysts, and because ovarian cysts are not part of the definition of PCOS, ultrasound is not routinely ordered to diagnose PCOS. The diagnosis is usually a clinical one based on the patient's history, physical examination, and laboratory testing.  More powerful and expensive imaging methods such as computed tomography (CT scan) and magnetic resonance imaging (MRI) also can detect cysts, but they are generally reserved for situations in which other conditions that may cause related symptoms, such as ovarian or adrenal gland tumors are suspected. CT scans require X-rays and sometimes injected dyes, which can be associated with some degree of complications in certain patients.

 Complications

The risk of developing prediabetes and type 2 diabetes is increased in women with PCOS, particularly if they have a family history of diabetes. Obesity and insulin resistance, both associated with PCOS, are significant risk factor for the development of type 2 diabetes. Several studies have shown that women with PCOS have abnormal levels of LDL ("bad") cholesterol and lowered levels of HDL ("good") cholesterol in the blood. Elevated levels of blood triglycerides have also been described in women with PCOS. Changes in skin pigmentation can also occur with PCOS. Acanthosis nigricans refers to the presence of velvety, brown to black pigmentation often seen on the neck, under the arms, or in the groin. This condition is associated with obesity and insulin resistance and occurs in some women with PCOS.

 Treatments

   Treatment of PCOS depends partially on the woman's stage of life. For younger women who desire birth control, the birth control pill, especially those with low androgenic (male hormone-like) side effects can cause regular periods and prevent the risk of uterine cancer. Another option is intermittent therapy with the hormone progesterone. Progesterone therapy will induce menstrual periods and reduce the risk of uterine cancer, but will not provide contraceptive protection. For acne or excess hair growth, a water pill (diuretic) called spironolactone (Aldactone) may be prescribed to help reverse these problems. The use of spironolactone requires occasional monitoring of blood tests because of its potential effect on the blood potassium levels and kidney function. Eflornithine (Vaniqa) is a cream medication that can be used to slow facial hair growth in women. Electrolysis and over-the-counter depilatory creams are other options for controlling excess hair growth.  For women who desire pregnancy, a medication called clomiphene (Clomid) can be used to induce ovulation (cause egg production). In addition, weight loss can normalize menstrual cycles and often increases the possibility of pregnancy in women with PCOS. Other, more aggressive, treatments for infertility (including injection of gonadotropin hormones and assisted reproductive technologies) may also be required in women who desire pregnancy and do not become pregnant on Clomid therapy.  Metformin (Glucophage) is a medication used to treat type 2 diabetes. This drug affects the action of insulin and is useful in reducing a number of the symptoms and complications of PCOS. Metformin has been shown to be useful in the management of irregular periods, ovulation induction, weight loss, prevention of type 2 diabetes, and prevention of gestational diabetes mellitus in women with PCOS.  Obesity that occurs with PCOS needs to be treated because it can cause numerous additional medical problems. The management of obesity in PCOS is similar to the management of obesity in general. Weight loss can help reduce or prevent many of the complications associated with PCOS, including type 2 diabetes and heart disease. Consultation with a dietician on a frequent basis is helpful until just the right individualized program is established for each woman.  Finally, a surgical procedure known as ovarian drilling can help induce ovulation in some women who have not responded to other treatments for PCOS. In this procedure a small portion of ovarian tissue is destroyed by an electric current delivered through a needle inserted into the ovary.

Wednesday, March 23, 2011

Chronic Diarrhea


Chronic Diarrhea 

A 21 year-old male presents with a 6-week history of watery diarrhea
and crampy abdominal pain. He reports that the diarrhea has not been constant and has alternated with periods of constipation. For the past 2 weeks, the diarrhea has been blood-streaked and he has had several weeks of midepigastric pain. He spent the past 6 months in a rural community in Guatemala participating in a community service project sponsored by his college. He returned from Guatemala just 10 days ago. While there, he drank the water and ate the food available in the local community, and he did not routinely boil water for drinking. He denies antibiotic exposure but has taken mefloquine weekly for malaria prophylaxis. Two separate stool specimens taken by student health when he returned were
reported as negative for Salmonella, Shigella, Campylobacter, E. coli O157:H7, Yersinia, Aeromonas, and Pleisiomonas as well as Giardia lamblia. On physical examination he appeared well nourished and well developed but reports an 8–10 lb weight loss. 
LABORATORY TESTS
Just as with acute diarrhea, the history of a patient’s illness frequently
provides clues to the etiology of the disease. The length of illness and
travel history of this patient plus abdominal findings and weight loss
are key features. Diarrhea with blood narrows infectious causes to agents such as Shigella, Salmonella, Campylobacter, EHEC, EIEC, and Entamoeba histolytica. An evaluation for chronic diarrhea requires a stool culture (×3), ova and parasite exam of stool (×3), and guaiac test of stool for occult blood. Because of this patient’s abdominal findings, liver function tests such as alkaline phosphatase and serum transaminases should also be ordered. Whenever liver abscess is suspected, abdominal ultrasound or computed tomography (CT scan) should also be performed.
Because both bacteria and parasites can be shed intermittently in stool, multiple stool specimens should be submitted for both bacterial culture and ova and parasite examination. See Case 3 for information on stool collection and transport for bacterial culture. For parasite analysis, specimens should be taken on separate days (every other day if possible) to increase likelihood of detection. Stool specimens collected for parasite analysis should be submitted in preservation vial(s) designed for this purpose.
  All forms of parasites (ova, larvae, protozoa, worms) can be
maintained at room temperature for long periods of time (months) using preservation vials. In addition, concentration procedures to recover small numbers of protozoan cysts, eggs, and larvae can be performed using the vials, and permanent stained smears can be prepared as well. If preservation vials are not available, then stool should be collected in clean, dry, wide-mouthed containers with tight-fitting lids. The stool should not be contaminated with urine because the pH of urine can destroy motile parasites. Liquid stool specimens must be examined by the laboratory within 30 min after they were taken from the patient, or some parasitic forms will disintegrate. If this rapid transport time is not possible, then preservation vials should be used. Results of an initial ova and parasite stool examination showed that the specimen was positive for cysts of E. histolytica/E. dispar. With this additional information, a serology test for E. histolytica antibodies and an abdominal CT scan were ordered.
E. histolytica, the cause of intestinal amebiasis and amebic liver abscess, can be diagnosed in the laboratory using a variety of methods:
1. Microscopic exam (stool, liver abscess). Microscopic identification of E. histolytica cysts or trophozoite (ameboid) forms is the most common method used to diagnose the infection; however, it is both insensitive and nonspecific. The test is nonspecific because E. histolytica cysts cannot be morphologically distinguished from those of Entamoeba dispar, a harmless commensal, unless ingested RBCs are present inside the trophozoite. Microscopic examination of liver abscess material is a poor way to attempt the diagnosis of amebiasis. While the abscess material is known to have the appearance of “anchovy paste,” ameba are rarely visualized in the material because they have disintegrated.
2. Antibody detection (serum). Serology studies [indirect hemagglutination, gel diffusion, enzyme-linked immunosorbent assay (ELISA)] to detect antibody to E. histolytica are positive in >90% of patients who have invasive disease. In the vast majority of patients antibodies are detectable after 7–10 days. When patients no longer have detectable parasites in their stools, detection of antibodies is critical for diagnosis of amebic liver abscesses.
TREATMENT AND PREVENTION
Two classes of drugs are used to treat E. histolytica infections. (1) a luminal amebicide, such as iodoquinol, which destroys parasites in the lumen of the intestine but does not kill ameba in tissue; and (2) a tissue amebicide, such as metronidazole or chloroquine, which treats invasive amebiasis but is less effective in the lumen. Amebic dysentery may be treated with iodoquinol and metronidazole. Extraintestinal disease is treated with a combination of
metronidazole and chloroquine. To follow the clinical response of intestinal disease to therapy, a repeat stool exam for parasites should be done 2–4 weeks after treatment, and extraintestinal disease should be monitored by repeat CT scans. Repeat serology tests are of little use since antibody titers remain elevated in spite of response to therapy. Prevention of infection with E. histolytica involves drinking boiled or bottled water when traveling to developing nations, and avoiding uncooked foods that may have been washed in water, such as salad.

Vomiting and Diarrhea after a School Picnic


 Vomiting and Diarrhea after a School Picnic

 PATIENT HISTORY

   A 14-year-old male presented to his pediatrician for evaluation of vomiting,abdominal discomfort, and nonbloody diarrhea. Three days prior, he attended his school picnic, where he ate everything offered: barbecued chicken, potato salad, baked beans, tossed salad, and ice cream . Within 36 h of the picnic he noted mild abdominal discomfort, intermittent crampy abdominal pain, and three to five loose, watery bowel movements per day. He reported no blood in the stool, rash, pain on urination (dysuria), or blood in the urine (hematuria) and had no travel history, had no pets, and denied taking antibiotics. The school reports that at least 50 other students who attended the picnic are also reporting similar symptoms. 

LABORATORY TESTS
There are various interpretations of what is considered medically indicated for evaluating persons with acute diarrhea. Because most diarrheal illness is self-limited, the usefulness of stool cultures is questioned by some; however, early diagnosis can lead to interventions that both alleviate symptoms and prevent secondary transmission, which can have tremendous public health impact. In addition, detection of specific agents aids in the timely detection and control of outbreaks. Some causes of acute diarrhea can result in serious long-term sequelae such as Guillain–Barr´e syndrome (with
Campylobacter) or hemolytic uremic syndrome (HUS) due to EHEC, further justifying the need for performing stool culture. A stool specimen for culture should be obtained as early in the course of the disease as possible from all patients with bloody diarrhea, patients with fever, in persons with diarrhea who are immunosuppressed, from patients in whom the diagnosis of HUS is suspected, and from persons involved in possible outbreaks.
Pathogenic bacteria can be identified by isolating the organism by
culture and/or by identifying a characteristic marker for virulence such
as a toxin. Routine bacterial stool cultures can identify Campylobacter, Salmonella, Shigella,Yersinia enterocolitica, Aeromonas hydrophila, Pleisiomonas  shigelloides, and noncholera Vibrio spp. Special media are required to identify E. coli O157:H7 and Vibrio cholera, and laboratory personnel should be notified when such agents are suspected. In addition to culture, E. coli
O157:H7 can also be diagnosed using a toxin assay that detects shiga toxins produced by all EHEC types. Toxin assays rather than culture are routinely used for diagnosing Clostridium difficile diarrhea.
Because an outbreak was suspected from the school picnic our case
patient attended, a stool culture was performed despite the fact that he had a mild self-limited illness. A routine bacterial stool culture would be appropriate in this case since Salmonella, Shigella, or Campylobacter spp. would be the most likely causes. His lack of bloody diarrhea would make EHEC, such as E. coli O157:H7, less likely. His lack of travel history indicates that his specimen does not need to be screened for organisms found outside his geographic area, and the absence of antibiotic use makes testing for toxins of C. difficile less of a priority.
Because there is no specific antiviral treatment available, testing for viral causes of gastroenteritis is not routinely performed except in outbreak situations or hospital settings. Testing for rotavirus, a major cause of fever, vomiting, and watery diarrhea in infants and young children, is routinely performed in hospitals so that patients can be cohorted and infection control practices emphasized. Rotavirus is commonly seen during the winter months (October–March).
Feces should be submitted in a clean, dry, plastic or waxed cardboard container with a tight-fitting or screwcap lid. Once collected, the specimen can be maintained at room temperature during transport. Rectal swabs should be used only with infants and young children fromwhomcollecting feces may be difficult and again should be taken only during acute disease. For an adequate specimen, the swab should be inserted past the anal sphincter into the rectum, and feces should be obvious on the swab when
removed. If the specimen (feces or swab) will not be processed or reach the laboratory within 1 h, an enteric transport medium should be inoculated with the feces and this will be stable for as long as 72 h at room temperature. In addition to stool, blood cultures should also be obtained from patients who have fever and diarrhea.

 TREATMENT AND PREVENTION
 The first line of therapy is supportive treatment, to return the patient to fluid and electrolyte balance. The patient may drink an oral rehydration solution that contains water, salt, and sugar, or liquids such as Pedialyte, which have the appropriate electrolytes and fluids to replace those being lost. Most cases of gastroenteritis are self-limited and require no antibiotic therapy. In fact, antibiotics are contraindicated in some cases. Giving antibiotics for Salmonella gastroenteritis prolongs the carriage of the organism in the GI tract and can lead to the person retaining the organism for months. Treatment of E. coli O157:H7 may increase the risk of hemolytic
uremic syndrome (HUS) in children and should be avoided. Likewise, one should avoid using antimotility agents in cases with bloody diarrhea or proven EHEC infection.
Patients who are very young or immunosuppressed may require antibiotics to recover from their disease. Patients with Shigella gastroenteritis are more likely to be sicker and require antibiotic therapy than are patients with Salmonella or Campylobacter gastroenteritis. Ampicillin, SXT, or ciprofloxacin are common choices for antimicrobial therapy because they can be administered orally if the patient can tolerate drinking liquids. Since the organism may be resistant to one or more of these antimicrobials, susceptibility results for the patient’s organism should guide the physician’s choice.
According to surveillance by the Centers for Disease Control and Prevention (CDC), Campylobacter jejuni is the most common enteric pathogen seen in adult patients with diarrhea, whereas Salmonella is the most common in children. Campylobacter spp. are not susceptible to penicillins or cephalosporins. Ciprofloxacin and erythromycin are the drugs of choice.
If a patient is hospitalized with enteric fever (S. typhi), a thirdgeneration cephalosporin is usually given intravenously. Our case patient has an infection with Salmonella susceptible to ampicillin, SXT, and ciprofloxacin. Because he is a healthy young adult, only supportive treatment
was given.

Monday, March 21, 2011

Student with Dysuria



Student with Dysuria

 PATIENT HISTORY
A 20-year-old college student complained of burning when urinating and a strong desire to void frequently although she had little urine to void. She was not experiencing any pelvic pain or discharge. Her symptoms beganshortly after she returned from a weekend visit to her boyfriend’s school.
She went to her university health service for diagnosis and treatment. On exam she was without fever and had moderate suprapubic tenderness, but
no flank tenderness.


LABORATORY TESTS

Urine Dipstick
A urine specimen was collected from this patient by a noninvasive technique,a midstream clean catch. Screening tests can predict which urine specimens contain a high colony count of bacteria. The most frequently used screening test with urine is called a “dipstick test”. A dipstick consists of plastic strips that contain multiple pads with chemical indicators. Normal urine is sterile, without protein, white cells, blood, or nitrites. A positive test for nitrites indicates the presence of bacteria that produce nitrate reductase, changing nitrate to nitrite. A positive test for leukocyte esterase indicates the presence of polymorphonuclear neutrophils (PMNs) in the urine that produce the enzyme. Inflammatory cells are the host’s response to infection. The strip is dipped into the urine, and the indicator
pads turn colors that are read immediately and compared to a scale of +to +4 . A dipstick test performed at the university health center on the urine from our college student showed positive reactions for both nitrate and leukocyte esterase, so her urine was sent to the lab for culture. A urine culture should be performed in patients with suspected cystitis regardless of dipstick results.

 TREATMENT AND PREVENTION

Factors to consider when treating UTI include:
Patient’s age and sex
Symptomatic versus asymptomatic infection
Upper (pyelonephritis) versus lower (cystitis) urinary tract involvement
Community- versus hospital-acquired infection
Single event versus recurrent events
Patient’s underlying illness
For uncomplicated cystitis a 3-day course of treatment is recommended. Symptoms usually resolve over 1–3 days. Many antibiotics with a broad range of activity against gram-negative rods and/or gram-positive cocci are suitable for the treatment of UTI, whether they are bacteriostatic or bacteriocidal drugs because they are concentrated 10–30-fold in the urine. Choices for initial empiric treatment of uncomplicated UTI in women include trimethoprim–sulfamethoxazole, a fluoroquinolone, or nitrofurantoin. The choice of an empiric antibiotic should always be based on the local prevalence of resistance in one’s geographic area, and this should be
periodically reevaluated. Ampicillin, amoxicillin, and sulfonamides are no longer considered good empiric choices because of the higher resistance rates seen in Enterobacteriaceae and Enterococcus spp. isolated from adults. Follow-up urine cultures are not necessary for patients with uncomplicated cystitis who respond clinically to treatment. Pregnant women should receive a follow-up culture 1–2 weeks after treatment. Complicated UTIs are more often caused by bacteria that may be resistant to the antibiotics used to treat uncomplicated UTI, particularly in hospitalized patients. Until the results of urine cultures are available in these patients, a fluoroquinolone is an excellent antibiotic choice in adult patients. In
these patients, treatment should be continued for 7–14 days. If symptoms resolve, a follow-up urine culture is not generally recommended.

Thursday, March 17, 2011

Liver blood test


 Liver blood test

An initial step in detecting liver damage is a simple blood test to determine the presence of certain liver enzymes (proteins) in the blood. Under normal circumstances, these enzymes reside within the cells of the liver. But when the liver is injured for any reason, these enzymes are spilled into the blood stream. Enzymes are proteins that are present throughout the body, each with a unique function. Enzymes help to speed up (catalyze) routine and necessary chemical reactions in the body.
Among the most sensitive and widely used liver enzymes are the aminotransferases. They include aspartate aminotransferase (AST or SGOT) and alanine aminotransferase (ALT or SGPT). These enzymes are normally contained within liver cells. If the liver is injured or damaged, the liver cells spill these enzymes into the blood, raising the enzyme levels in the blood and signaling the liver disease.

 Aminotransferases

The aminotransferases catalyze chemical reactions in which an amino group (amino acids are building blocks of proteins) is transferred from a donor molecule to a recipient molecule. Hence, the names "aminotransferases."
Medical terms can sometimes be confusing, as is the case with these enzymes.
·                          Another name for aminotransferase is transaminase. 
·                          The enzyme aspartate aminotransferase (AST) is also known as serum glutamic oxaloacetic transaminase (SGOT); and 
·                          alanine aminotransferase (ALT) is also known as serum glutamic pyruvic transaminase (SGPT).
To put matters briefly, AST = SGOT and ALT = SGPT.

 Normal levels of AST and ALT

The normal range of values for AST (SGOT) is from 5 to 40 units per liter of serum (the liquid part of the blood).
The normal range of values for ALT (SGPT) is from 7 to 56 units per liter of serum.
The ranges of AST and ALT numbers may differ slightly depending on the technique and protocols used by different laboratories. However, normal reference ranges are routinely provided by each laboratory and printed in the report.

Medications cause abnormal aminotransferase levels

A host of medications can cause abnormal liver enzymes levels.
Examples include:
Pain relief medications such as:
·                          aspirin, 
·                          acetaminophen (Tylenol), 
·                          naproxen (Narcosis, Nap élan, Anaprox, Aleve), 
·                          diclofenac (Voltaren, Cataflam, Voltaren-XR), and 
·                          phenylbutazone (Butazolidine)
Anti-seizure medications such as:
·                          phenytoin (Dilantin), 
·                          valproic acid (Depakote, Depakote ER, Depakene, Depacon), 
·                          carbamazepine (Tegretol, Tegretol XR, Equertro), and 
·                          phenobarbital
Antibiotics such as:
·                          tetracyclines, [for example, tetracycline (Achromycin)]
·                          sulfonamides, 
·                          isoniazid (INH) (Nydrazid, Laniazid)
·                          sulfamethoxazole (Gantanol), 
·                          trimethoprim (Trimpex; Proloprim, Primsol)
·                          nitrofurantoin (Macrodantin; Furadantin; Macrobid), 
·                          fluconazole (Diflucan ) and some other anti-fungals, etc.
Cholesterol lowering drugs such as:
·                          the statins:
o                                         lovastatin (Mevacor, Altocor), 
o                                         pravastatin (Pravachol), 
o                                         atorvastatin (Lipitor),
o                                         fluvastatin (Lescol),
o                                         rosuvastatin (Crestor),
o                                         simvastatin (Zocor), and

·                          niacin
Cardiovascular drugs such as:
·                          amiodarone (Cordarone),
·                          hydralazine (Apresoline) 
·                          quinidine (Quinaglute, Quinidex), etc.
Other drugs
·                          Antidepressant drugs of the tricyclic type
With drug-induced liver enzyme abnormalities, the enzymes usually normalize weeks to months after stopping the medications.



Wednesday, March 16, 2011

Acute Pharyngitis


 Acute Pharyngitis

 PATIENT HISTORY
The patient was a 6 year-old male who had been in good health with no significant medical problems. In late September he presented to his pediatrician’s office with a complaint of sore throat, fever, headache, and swollen glands in his neck for the past 36 h. On physical examination
(PE), he had a fever of 38C (100.4F), a red posterior pharynx, yellowish exudate on his tonsils, and multiple, enlarged, tender cervical lymph nodes.
 There were no other pertinent symptoms.

LABORATORY TESTS
  pain on swallowing, as well as erythema with or without exudate on the
tonsils and tender cervical lymph nodes. There are no clinical indicators
that would make it possible to accurately predict the cause of this child’s
pharyngitis. Laboratory tests are required to make a diagnosis.
When deciding whether to perform a laboratory test, clinical and epidemiological
features as well as the availability and usefulness of treatment
must be considered. While viruses are the most common cause
of acute pharyngitis in both adults and children, lab testing for viruses
is not warranted because antiviral agents are not used to treat acute
pharyngitis. Given the age of this patient, the absence of travel, and the
lack of suspicion of child abuse, GAS is the most likely etiologic agent.
Since GAS pharyngitis is the most commonly occurring form of pharyngitis
for which antibiotic therapy is indicated, lab testing should be directed
at ruling out GAS. Appropriate laboratory tests for this would
include:
Rapid strep test. This is not a culture; the test detects a unique carbohydrate
on the cell wall of GAS.
Throat culture. This test will grow the GAS organism from a throat
specimen taken from the patient and will require overnight incubation
at the minimum. Most labs offer a specific “rule out GAS”
throat culture.
The specimen required for each of these tests is a throat swab. Use of a
double-swab format allows one to obtain sufficient specimen to perform
both tests if necessary. As with any microbiology test, the quality of the
results is contigent on whether the laboratory receives a well-taken specimen.
The double swab should be firmly rubbed over much of the surface
of both tonsils and the posterior pharyngeal area and rolled to ensure
that there is ample specimen is on each swab tip. If exudate is present, it
should also be sampled on the same swabs. Care should be taken to avoid
touching other areas of the oropharynx, mouth, and tongue.
DirectGramstains fromthroat swabs are not at all useful becausemany
bacteria normally reside in the throat, including nonpathogenic streptococci
that have Gram stain appearance identical to that of GAS.

 TREATMENT AND PREVENTION

Treatment of group A streptococcal pharyngitis is important in order to
relieve the patient’s symptoms and to prevent the transmission to others.
Prompt treatment will also prevent complications such as peritonsillar abscess
and acute rheumatic fever. Symptoms will often disappear within
3–4 days even without antibiotics, but early antibiotics can shorten the
duration of symptoms. Pharyngitis caused by S. pyogenes can be effectively
treated with a penicillin. In children, like this patient, amoxicillin
is routinely prescribed. Patients must complete the course of antibiotic to
eradicate the organisms from the pharynx. For patients who are allergic
to penicillin, erythromycin would be an acceptable alternative. If left untreated,
patients with GAS infection may develop the sequellae of heart
valve damage (RF) or kidney damage (GN).
Susceptibility tests on GAS would not be performed since resistance
to penicillin has not been documented in these organisms to date. Carriers
maintain S. pyogenes in their throats despite appropriate antibiotic therapy;
it is not because the organisms are resistant to penicillin. Carriers are not
symptomatic but can spread the organism to others who may develop an
infection.