Infectious Disease

ABSTRACT: A scheme-based approach, supported by a simple mnemonic, can narrow the broad differential diagnosis of thrombocytopenia. This approach uses findings from the complete blood cell count and the peripheral smear to organize the possible causes of thrombocytopenia into those that affect only platelet count, those that produce both a low platelet count and hemolytic anemia, and those that produce disturbances in all 3 blood cell lines. Causes of isolated thrombocytopenia include viral infections, immune-mediated platelet destruction, congenital diseases, gestational thrombocytopenia, conditions in which splenomegaly is a prominent feature, antiphospholipid antibody syndrome, infectious diseases of bacterial origin, and drugs. Causes of thrombocytopenia in conjunction with hemolytic anemia include hemolytic uremic syndrome, thrombotic thrombocytopenia purpura, and disseminated intravascular coagulation. Disorders that produce disturbances in all 3 blood cell lines include aplastic anemia, myeloproliferative syndromes, myelodysplasia (both primary and secondary), myelofibrosis, myelophthisis, and several other diseases in which splenomegaly is prominent.

16-month-old previously healthy child is hospitalized after 36 hours of worsening painful edema and erythema of the right lower leg and high fever with chills.

ABSTRACT: A number of nondental conditions may cause significant oral pain. Pain associated with temporal arteritis is localized to the maxillary posterior teeth, the maxilla, or the frontal-temple region. This pain is often associated with exquisite tenderness of the scalp and face. The pain of trigeminal neuralgia is typically felt in the anterior maxillary or mandibular anterior teeth; it radiates along the mandible toward or into the ear on the ipsilateral side of the trigger. Pain may remit for months or years but is often severe when it recurs. Burning mouth syndrome preferentially affects postmenopausal women older than 50 years; one half to two thirds of patients experience spontaneous remission within 6 to 7 years, with or without treatment. The pain of postherpetic neuralgia is unilateral and restricted to the affected dermatome; it may be aggravated by mechanical contact or chewing.

A 56-year-old woman presents for a routine examination. She has been healthy, and results of previous examinations have been normal.

Erythema and bulla formation characterize the typical lesions of superficial frostbite. Deep frostbite, in contrast, involves subcutaneous tissue and usually leads to tissue loss.

For 2 months, a 19-year-old woman has had a slightly tender acneiform eruption on the trunk that spread to the extremities.

An 18-year-old girl presented with an asymptomatic nodule on the posterior aspect of the right upper arm. The lesion had developed a month after an episode of chickenpox at 11 years of age and had slowly enlarged. The lesion was 7 mm in diameter; it was firm, rubbery, reddish brown, and nontender.

A 45-year-old man was referred to our pulmonary clinic for progressive dyspnea and worsening asthma. His shortness of breath had been worsening over the past 2 years. He denied fever, weight loss, and other systemic complaints.

In the October 2004 issue of TheJournal of Respiratory Diseases,Morrison and Gupta1 reviewed theclinical and laboratory approachesto the diagnosis of communityacquiredpneumonia (CAP) causedby Legionella. They discussed theadvantages and limitations of culture,direct fluorescent antibody(DFA) staining, serology, polymerasechain reaction, and Legionellaurinary antigen assays. As the authorsnoted, DFA staining of respiratorysecretions is an underusedtest that has a high specificity in patientswith untreated Legionnairesdisease.

Scott and associates described a case of Phialemonium obovatum fungemia in a bone marrow transplant recipient. This fungal infection was associated with caseating granulomata in the lungs and GI involvement that resembled Crohn disease.

Although lipoprotein levels are known to be reduced in critically ill patients, the prognostic significance of this in patients with sepsis has not been established. However, a study recently conducted in Taiwan is worth noting; it found that low levels of high-density lipoprotein (HDL) cholesterol on day 1 of severe sepsis were associated with increased risk of death.

Abstract: The manifestations of indoor mold-related disease (IMRD) include irritant effects, such as conjunctivitis and rhinitis; nonspecific respiratory complaints, such as cough and wheeze; hypersensitivity pneumonitis; allergic fungal sinusitis; and mycotoxicosis. The diagnosis of IMRD depends on eliciting an accurate history and excluding preexisting pathology that would account for the patient's symptoms. Laboratory tests, imaging studies, and spirometry can play an important role in ruling out other diagnoses, such as allergic or nonallergic rhinitis, asthma, and pneumonia. The diagnosis of IMRD also involves integrating the results of immunologic, physiologic, and imaging studies with the results of indoor air-quality studies. (J Respir Dis. 2005;26(12):520-525)

Abstract: Spinal tuberculosis is the most common form of osteoarticular involvement in patients with tuberculosis. Localized pain is a common presenting symptom. In patients who do not present until vertebral wedging and collapse have occurred, a localized knuckle kyphosis is obvious, especially in the dorsal spine. In some patients, a retropharyngeal abscess develops, causing dysphagia, dyspnea, and/or hoarseness. Peripheral joint tuberculosis is characterized by an insidious onset of slowly progressive, painful, and swollen monoarthropathy, most commonly affecting the hip or knee. The radiologic features include juxta-articular osteoporosis, peripheral osseous erosion, and gradual narrowing of the interosseous space. Treatment involves antituberculosis drugs; the indications for surgery are relatively limited. (J Respir Dis. 2005; 26(12):543-546)

A 25-year-old man presented to the emergency department with left scrotal swelling. He mentioned that he also had severe intermittent right-sided chest pain of 1 week's duration that began while he was lifting heavy items at work. The pain worsened with exertion and was relieved by rest. There was no radiation to the shoulder or back. The patient's medical history was otherwise not significant.

Abstract: Acute chest syndrome (ACS) is one of the most common causes of death and hospitalization among patients with a sickle hemoglobinopathy. The clinical presentation is characterized by the appearance of a new infiltrate on a chest radiograph, with 1 or more new symptoms, including fever, cough, chest pain, and dyspnea. Additional findings include leukocytosis, hypoxemia, and auscultatory signs of consolidation. The differential diagnosis includes pneumonia, pulmonary infarction, fat embolism syndrome, pulmonary edema, and bone infarction. Treatment of ACS involves supportive care, empiric antibiotic therapy, and red blood cell transfusion when indicated. The decision of whether to use simple or exchange transfusions depends on the severity of illness and the risk of acute respiratory failure. Currently, hydroxyurea is the only FDA-approved drug designated as a preventive therapy. (J Respir Dis. 2005;26(12):529-534)

A 16-year-old boy visiting his aunt and uncle at a cabin in the country was bitten by their cat earlier in the day. He tried to pick up the animal after it had been injured, and it bit him on the dorsum of the hand between the thumb and first finger.

A 57-year-old woman complains of burning and dryness in her left eye and altered sensation in her mouth when eating; these symptoms began the day before. A coworker who had noticed facial asymmetry recommended that she seek medical attention.

I am concerned about Dr Benjamin Barankin's recent "Photoclinic" case of an alleged brown recluse spider bite.

A 49-year-old man has had dyspnea on exertion for 1 month; it has worsened during the past 2 days. He has also had 2 episodes of epistaxis and increasing abdominal distention, without pain, during the past 6 months.

Chronic diarrhea presents difficulties for clinicians as well as for patients. Because the differential diagnosis is enormous, management can be challenging. In this article, we present a strategy for quickly narrowing the differential based on a simple analysis of stool characteristics. We then describe an appropriate workup for each of the basic types of diarrhea.

Low back pain is a widespread and costly complaint that affects virtually all Americans at some point in their lives. After the common cold, it is the second most frequent cause of work absence in the United States.

A 2 1/2-year-old child is hospitalized with a 1-month history of worsening persistent cough. She was initially treated with a 5-day course of oral amoxicillin, and her symptoms abated somewhat. However, for the past week, she has experienced high fever and chills associated with right-sided pleuritic chest pain.

An asymptomatic acneiform eruption; persistent, mildly pruritic papules; a pustular rash that resists antibiotics--can you identify the disorders pictured here?

A 51-year-old man with a history of AIDS (CD4 count of 59 cells/µL), anemia, neutropenia, and AIDS-related dementia presented with persistent fever, abdominal pain, and diarrhea of 2 months' duration. He did not adhere to his regimen of HAART and prophylactic therapy with atovaquone and azithromycin.

A 36-year-old homosexual man presented with a 2-week history of odynophagia to liquids and solids; he had no dysphagia or heartburn. The patient, who had been seropositive for HIV for 3 years, had refused all antiretroviral drugs and prophylactic agents against opportunistic infections.