Lepromatous leprosy is a rare disease affecting the skin and peripheral nerves that should be considered in patients from endemic areas who present with a rash. Rarely, leprosy may present with erythema nodosum. Early recognition of this disease is important as early leprosy treatment is essential to avoid complications.
A 23-year-old man presented to the emergency department with evolving rash over two weeks. The rash was non-pruritic and started on his lower limbs and gradually spread upwards to the rest of his body, including his face and ears. One week after the rash appeared, he developed fever and generalized pain in his hand and foot joints.
The patient had no allergies and no family history of skin disease. He was born in the Marshall Islands but had been living in the United States for the past five years. He had no known history of STDs. He had no recent history of international travel and none of his close contacts had had a similar rash.
Physical examination revealed multiple erythematous nodules and papules on the head and neck, disseminated brown and erythematous macules and papules on trunk and limbs, including hands. Palpable purpura and hyperpigmented patches were present on his lower anterior legs. Mild synovitis of his finger joints and bilateral inguinal lymphadenopathy were present. There was no mucosal involvement.
Diagnostic testing revealed a white blood cell count of 3.0×109/L and erythrocyte sedimentation rate of 80mm/hr. A skin biopsy was performed and was histologically diagnostic of lepromatous leprosy. Cytology also demonstrated neutrophilic infiltrate and karyorrhectic debris consistent with erythema nodosumleprosum. Fite stain demonstrated numerous intracellular acid-fast bacilli. Amodified treatment protocol consisting of dapsone, rifampin, and moxifloxacin was initiated. In addition, the patient was treated with prednisone for inflammatory symptoms.
This case describes erythema nodosum with systemic symptoms as an atypical presentation of lepromatous leprosy. It illustrates the importance of maintaining a high clinical suspicion for leprosy in a patient who presents with a disseminated erythematous nodular and maculopapular rash. Although it is rare, it should be included in the differential for an unexplained rash in a patient from an endemic area.