Systemic phaeohyphomycosis caused by Exophiala dermatitidis

Abstract

Summary. We report a case of systemic phaeohyphomycosis due to Exophiala dermatitidis in a 24‐year‐old man. At the age of 17, the patient had noticed cervical swellings. On palpation at his initial examination, more than a dozen firm lymph nodes between 1 and 5 cm in diameter were found on both sides of the neck and in both axillae. Examination of biopsy specimens of lymph nodes revealed pale brown hyphae in granulomatous lesions and Exophiala dermatitidis was isolated from mycological cultures of the local tissues. The clinical course was marked by an episode of jaundice six months later, and surgery disclosed a fist‐sized inflammatory mass in the region of the head of the pancreas and the duodenum. The patient was treated by providing external biliary drainage and by the administration of antifungal agents, but two years later complained of diplopia and a slight heaviness in the head. Computed tomographic scans were made of the head, revealing multiple plum‐sized masses in the brain. The patient died a year later. In Japan, 10 cases of systemic infection by this organism (including the present one) have been reported, all in patients of up to 30 years of age, with lesions appearing in the brain, lung, liver, digestive organs and lymph nodes. The prognosis is grave. Zusammenfassung. Unser Bericht beschreibt einen Fall von systemischer Phäohyphomykose, verursacht durch Exophiala dermatitidis, bei einem 24‐jährigen Mann. Im Alter von 17 Jahren hatte dieser Patient Schwellungen am Hals festgestellt. Bei der Palpation während der ersten Unter‐suchung wurde uber ein Dutzend fester Lymph‐knoten (1–5 cm Durchmesser) an beiden Seiten des Halses und in beiden Achselhöhlen gefunden. Die Gewebsuntersuchung eines Lymphknotens zeigte hellbraune Hyphen in einer granulomatö‐sen Verletzung, und Exophiala dermatitidis wurde von einer mykologischen Kultur des lokalen Gewebes isoliert. Der klinische Verlauf war durch das Auftreten von Gelbsucht sechs Monate später gekennzeichnet, und bei einer Operation wurde eine faustgroße entzündete Masse im Bereich des Pankreaskopfes und des Zwälffingerdarms festgestellt. Der Patient wurde mit einer externen Gallengangdrainage versehen und mit Antimyko‐tika behandelt. Aber zwei Jahre später klagte er über Doppeltsehen und ein Schweregefuhl im Kopf. Der Kopf wurde mittels Computertomo‐graphie untersucht, und dabei wurden im Gehirn mehrere pflaumengroße Massen festgestellt. Der Patient starb ein Jahr spater. In Japan wurden bisher über 10 Fälle von systemischer Infektion durch diesen Organismus (den hier beschriebenen Fall eingeschlossen) berichtet. Alle traten bis zum Alter von 30 Jahren auf und waren gekenn‐zeichnet durch Läsionen im Gehirn, in Lunge, Leber, Verdauungsorganen und Lymphknoten. Die Prognose ist ernst.

Combination of Amphotericin B and Flucytosine against Neurotropic Species of Melanized Fungi Causing Primary Cerebral Phaeohyphomycosis

“…Infections by this fungus are reported mainly from East Asia, although several cases in other geographical regions worldwide have been reported (42,43). This fungus seems to be able to affect young, otherwise healthy patients (5,42,44,45). E. dermatitidis cerebral infection is generally associated with a high mortality rate (about 50%) (17).…”

Melanized Fungi in Human Disease

“…Disseminated infection is the most uncommon manifestation of infection caused by melanized fungi. In a review of 72 cases (627), most patients were immunocompromised, though occasional patients without known immunodeficiency or risk factors developed disseminated disease as well (3,24,73,76,95,105,119,171,208,238,242,246,288,291,308,321,345,386,389,397,400,402,403,409,423,424,435,471,485,516,538,543,550,557,578,593,595,596,612,621,627,640,647,672,688,712,713,740,…”

“…Exophiala dermatitidis is distinguished phenotypically by its mostly mucoid colonies, ability to grow at 40°C, lack of nitrate assimilation (569), and yeast cells surrounded by capsules (819), which it shares with another aggressive species, E. spinifera (180,214,536,699). The range of mycoses incited by E. dermatitidis include neurotropic infections in young, immunocompetent individuals (restricted to Asia) (138,345,492,494), systemic lymphadenitis (13), cutaneous and subcutaneous infections in mostly immunocompromised individuals (346,492), colonization of airways in cystic fibrosis patients (597), and mycoses related to continuous ambulatory peritoneal dialysis (CAPD) (783). It is also an opportunist in lungs of cystic fibrosis patients (320,355) and may be recovered from the stool in patients with diarrhea (178).…”

Molecular typing and antifungal susceptibility of Exophiala isolates from patients with cystic fibrosis

“…Exophiala (Wangiella) dermatitidis is a black yeast known for its ability to cause fatal infections of the central nervous system, particularly in Asian healthy individuals (Chang et al, 2000;Hiruma et al, 1993;Li et al, 2011;Matsumoto et al, 1993). The high virulence of this fungus can be attributed to its ability to grow at 37 u C and above (Padhye et al, 1978) and to the production of extracellular polysaccharides (Yurlova & de Hoog, 2002) as well as melanin (Langfelder et al, 2003).…”