Cutaneous mucormycosis in a chronic lymphocytic leukemia patient on ibrutinib

Mucorales is a zygomycete fungi known to cause opportunistic infections in immunosuppressed hosts. Spores may be inhaled, causing rhinocerebral or pulmonary infections, or gastrointestinal infections if swallowed. Less often, cutaneous mucormycosis develops after inoculation via broken skin.

A 72-year old male on ibrutinib and prednisone for chronic lymphocytic leukemia (CLL) presented with localized, right forearm cutaneous mucormycosis at the site of a dog-scratch sustained three weeks prior. The patient failed to respond to cephalexin as an outpatient, prompting biopsy showing ribbon-like pseudo septate hyphae and possible vascular invasion suggestive of Mucorales. Treatment course included liposomal amphotericin B 5 mg/kg IV every 24 h for ten days followed by a 90-day course of posaconazole 300 mg daily after general surgery consultation was sought.

We outline the second reported case of localized cutaneous mucormycosis arising in the setting of ibrutinib use. Because the combination of immunosuppressed states, ibrutinib and skin trauma may serve as a nidus for mucormycosis, practitioners should be vigilant of thorough skin evaluations in these patients and appropriate anti-fungal treatment. Although amphotericin B has been well studied as first line therapy, oral posaconazole has been shown as an efficacious second-line treatment.