0521779407-C03 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 20:54
364 Coccidioides Immitis■Epidemics associated with disruption of infected soil, by archaeo-
logic excavation or in severe dust storms or earthquakes
■All infections result from inhaling arthroconidia
■Exposure history is key to diagnosis – incubation usually 1–3 weeks,
but even brief/trivial exposures (driving through region, changing
planes at airport) have been implicatedSigns & Symptoms
■50–70% of infections inapparent or mild enough that medical atten-
tion not sought
■Many others experience nonspecific, self-limited respiratory illness
■Early respiratory infection:
➣Symptoms first appear 7–21 d after exposure
➣Cough, chest pain, dyspnea, fever, fatigue, weight loss, head-
ache
➣Skin manifestations: nonpruritic fine papular rash (early/
transient), also E nodosum and E multiforme (in females)
➣Triad of fever, e. nodosum, arthralgias=“desert rheumatism”
➣Uncommonly, fulminant respiratory failure/sepsis (1/3 of HIV
patients present this way)
■Pulmonary Nodules/Cavities:
➣4% pulmonary infections result in nodule (usually without symp-
toms), occ. forming a cavity
➣Most cavities do not cause symptoms – occ. pleuritic pain, cough,
hemoptysis
➣Can rupture into pleural space – often without immunodefi-
ciency, causes pyopneumothorax (prompt surgery indicated)
■Extrapulmonary Dissemination:
➣0.5% of all infections in general population
➣Increased risk with immunodeficiency (HIV, post-transplant,
high-dose steroids, Hodgkin disease)
➣Men>women, but high risk during third trimester of pregnancy
or immediate postpartum period
➣Increased risk among African or Filipino ancestry
➣Increased risk with waning T-cell immunity
➣Extrapulmonary dissemination often exists with no pulmonary
disease
➣Most common: skin – superficial maculopapular lesion, often
nasolabial fold; joints and bones
➣Most serious: Coccidioidal meningitis – headache, vomiting,
altered mental status