Infectious Disease

What is bovine spongiform encephalopathy(BSE), or “mad cow disease,” and how is itthought to infect cattle?

A 55-year-old constructionworker who spends a gooddeal of time outdoors has had occasionalblurred vision and an irritatedeyelid for several days. He has wellcontrolleddiabetes and hypertension.Which of these conditions doyou suspect?

Plague is caused by Yersiniapestis, a gram-negative, nonmotile,nonsporulating bacillus.It is a zoonotic disease, and rodentsare the primary reservoir.Plague can present as bubonic,pneumonic, or primary septicemic disease.Y pestis is usually transmitted tohumans via the bites of infected fleas,causing the bubonic form of the disease.Primary septicemic and secondarypneumonic disease are muchless common. Primary pneumonicdisease results from aerosol exposureto an infected animal or human withplague pneumonia; however, it too hasbecome uncommon as a natural event.Nonetheless, primary pneumonicplague, or a similar illness, is the mostlikely manifestation following a bioterroristattack.1,2 Despite the substantialinvestment by the former Soviet Unionin this agent as a potential weapon,there is little experience from whichto predict the clinical consequencesof intentional aerosolization of thisorganism.

A 51-year-old man presents with aseverely infected leg and 1- to 2-cmlesions on all of his extremities andtrunk; the bases of the lesions aredepressed, atrophic, and scarred.According to the patient, the lesionstypically appear as tender nodulesor pustules, which spontaneouslyburst, drain purulent material, andeventually heal as pictured.

In Dr Sean Eric Koon's Case In Point, "Puzzling Rash in an Older Woman"(CONSULTANT, April 15, 2003, page 629), I agree with his conclusion that thispatient had cutaneous leukocytoclastic vasculitis (CLV) (Figure). I also agreethat she met the American College of Rheumatology's 1990 criteria for a diagnosisof hypersensitivity vasculitis.1 However, given the patient's history and laboratoryresults, I believe further evaluation was warranted to determine whether the medication was indeed to blame for her CLV or whether an underlying systemicdisease was responsible.Her white blood cell (WBC) count was 72,000/?L. CLV is known to producea mild leukocytosis--presumably caused by the inflammatory response of the vasculitis.Thus, one would expect to see only a slight elevation in the WBC count.Also, if the elevation had been produced by the inflammatory response of the CLV,the patient's erythrocyte sedimentation rate (ESR) would have been significantlyelevated. However, her ESR was 12 mm/h, which is essentially normal in awoman this age.The discovery of a value that is not consistent with the disease process makesme question Dr Koon's final diagnosis--or at least want to add to his differentiala disease that could be responsible for both the CLV and the level of leukocytosisseen here: hairy cell leukemia.Other facts in the case that tend not to support the conclusion that the patient'sCLV resulted from a drug reaction include the following:One would expect to see systemic symptoms, such as fever, malaise, anorexia,and/or myalgias if a drug reaction caused the CLV; this woman reportedly didnot experience any of these.Rashes associated with CLV produced by a drug reaction are generally describedby patients as pruritic, painful (sometimes significantly so), and/or associatedwith paresthesias, such as a burning or stinging sensation; this patient's rash isdescribed as "painless and nonpruritic."Thus, although an exogenous agent such as trimethoprim-sulfamethoxazole(TMP-SMX) can cause CLV, it would have been prudent in view of the findingsin this case to search for an endogenous cause, such as an underlying systemicdisease or malignancy.----Pamela Moyers Scott, MPAS, PA-CWilliamsburg, WVaThank you for your comments. You detected a typo; this patient's leukocytecount was actually 7200/?L. A value of 72,000/?L would indeedbe of concern and would prompt a new differential diagnosis. HerWBC count when last checked was 7300/?L.Ultimately, my determination was that the patient's rash was mostlikely triggered by a viral infection and not by the TMP-SMX. I felt that anotherhealth care provider had inappropriately treated her upper respiratory tractinfection with an antibiotic, so I stopped the medication. Because I could notcompletely rule out the antibiotic as a cause of this potentially serious condition,I recommended that she avoid it in the future. This is yet another exampleof how the treatment of colds with antibiotics can confuse the clinical pictureand possibly harm the patient.--Sean Eric Koon, MD  &nbspFontana, Calif

All too often, when lancing a sebaceouscyst or abscess, or when relievingpressure from a traumatizednail bed, both practitioner and assistantare splattered with the materialthat is released.

A24-year-old man who worked ina warehouse is brought tothe emergency department following2 days of high fever with rigors, generalizedweakness, and a purplishrash on both lower legs that had progressedrapidly during the past24 hours. He had become ill about5 days previously, with a worseningsore throat and achiness that did notrespond to over-the-counter lozengesand ibuprofen.

Pandemics attributable to different influenza A virus subtypes occurredat irregular intervals throughout the 20th century. Because the timingof a pandemic cannot be predicted, we must be prepared for such an outbreak.Although influenza is generally viewed as an illness with potentiallydeadly effects primarily for elderly persons, it can lead to significant morbidityand mortality in otherwise healthy infants and toddlers and in other highriskgroups.

Before you collect a nasal swab for an influenza test,instruct the patient to repeatedly squeeze his or hernares just below the cartilage.

A 2-month-old infant is brought to the office by his parents becausehe has been crying inconsolably for the past 4 to 5 hours. The childhas been well since birth and has no history of vomiting, diarrhea, fever, orrash. The infant is being breast-fed, is not taking any medication, and hasnot been in contact with any sick persons.

If a sore throat persists even when antibiotics are used,counsel the patient to try this remedy.

What is the connection between cockroach allergy and wheezing or asthmain children?

Our laboratory has begun reporting group G β-hemolytic streptococci in addition to group A on throat cultures.

I have been a pediatrician/family physician for about 40years, and I have been exposed to most diseases.

Good nutritional care can improve the short-and longtermcourses of many illnesses that are common in olderadults. The experts who have contributed to this handbookdiscuss the disorders that can seriously affect andbe affected by nutrition, and they present specific recommendationsfor secondary prevention and management.

A46-year-old white man is hospitalized with increasing dyspnea of 3weeks’ duration. He has a history of stable chronic obstructive pulmonarydisease secondary to heavy smoking (2 packs of cigarettes a day for 27years, discontinued 6 years previously) and uses inhaled bronchodilators.

For 3 days, a 42-year-old man has had episodic dullchest pain. The anterior precordial and retrosternalpain intensifies with inspiration and movement. He has nohistory of recent viral infection, hypertension, coronaryartery disease, cardiac surgery, diabetes mellitus, or hyperlipidemia.There is no family history of cardiovasculardisease.

Use this ABCDE mnemonic to distinguishnecrotizing fasciitis, which usuallyrequires surgery, from cellulitis,which can be treated with antibioticsalone:

For the past month, a 19-year-old woman has had abdominalpain, diarrhea, intermittent fever, and occasionalvomiting. She now seeks medical attention because earlierin the day she noticed a large amount of blood in herstool. She denies trauma, travel to a foreign country, andillicit drug use. She drinks alcohol occasionally but hasnot done so for the past 3 months.

A 38-year-old overweight woman presents with an asymptomatic rash ofat least 2 months’ duration that had not responded to a combinationcorticosteroid/antifungal agent. She has mild hypertension and type 2 diabetesmellitus that is being managed with diet and exercise. She is otherwisehealthy.

In response to Dr Joseph Schube’s inquiry about a puzzlingurine culture that showed &#946-hemolytic streptococci (CONSULTANT,July 2002, page 974), I suggest that he consider oralintercourse as a possible source of the infection.

When a patient with diabetes presentswith a foot wound, prompt and aggressiveintervention is required topromote healing and to prevent progressionthat could lead to a leg amputation.Fortunately, the majority ofdiabetic foot wounds heal rapidly withlittle difficulty.

In Dr Navin Amin’s “What’s Wrong With This Picture?”case of a girl with infectious mononucleosis who had severepharygnitis and worsening dyspnea (CONSULTANT, December2003, page 1657), the patient was given parenteralhydrocortisone and later oral prednisolone.

A 7-year-old girl presents for evaluation of a pink, polypoid, 2 x 2-mm lesionon her inner lower lip, which has been present for several weeks. The child isasymptomatic and denies any trauma to the mouth.

My patient is a woman in her midtwentieswho recently presented with anerythematous, slightly pruritic lesionon her thigh.