Haemophagocytic lymphohistiocytosis driven by disseminated Mycobacterium haemophilum infection

Abstract

Mycobacterium haemophilum is a nontuberculous mycobacteria that primarily affects immunocompromised patients. It can lead to a wide variety of clinical manifestations including infections of the skin, soft tissue and joints. Due to the significant heterogeneity in clinical presentation and difficulty isolating the organism, diagnosis can be difficult and is often delayed. Our patient's course was further complicated by the development of haemophagocytic lymphohistiocytosis (HLH). Although M. tuberculosis infection is recognized as a potential association, HLH driven by a disseminated M. haemophilum infection has not yet been reported. Here we present a case of disseminated M. haemophilum infection in an immunocompromised patient who developed haemophagocytic lymphohistiocytosis.

Figure 1

Scaly erythematous plaques on the right cheek, nose and upper lip.

Figure 2

Representative photos of the patient's extremities. (a, b) Erythematous papules and scale on the upper left extremity and (c) right foot.

Figure 3

(a, b) Granulomatous dermatitis and chronic inflammation throughout the upper dermis with occasional giant cells and scattered acid-fast bacilli. The dermis shows fibrosis and reactive vascular ectasia. Haematoxylin and eosin, original magnification (a) ×10 and (b) ×20. (c, d) Acid-fast bacilli staining highlights small rod-shaped organisms consistent with mycobacteria. Fite, original magnification (c) ×20, and Kinyoun, original magnification (d) ×20.