Down the Rabbit Hole: Cutaneous Tuberculosis

The term “going down the rabbit hole,” based on Lewis Carroll’s Alice’s Adventures in Wonderland, is a metaphor for an entry into the unknown, the disorienting, or the mentally deranging. Although the case of a patient with a nonhealing ulcer did not set us on a path with these exact qualities, it did remind us that ulcers could, at times, be associated with unexpected diagnoses.

An 88-year-old Chinese man presented with a nonremitting, fixed, pruritic truncal rash that was unresponsive to antihistamines and topical corticosteroids. In addition, he had a 7-month history of a nonhealing perianal ulcer, for which he had been referred from his colorectal surgeon with the presumptive diagnosis of pyoderma gangrenosum. Previous biopsies yielded largely nonspecific results, although they did show granulomatous inflammation.

The patient had immigrated from Shanghai, China, 6 months previously and denied fever, chills, night sweats, or cough. He felt generally well, although his daughter noted an unspecified weight loss over the previous few months. Six weeks before the ulcer developed, he was treated for recurrent fecal impaction, which had required self-disimpaction and medical manual disimpaction. His medical history was also significant for lung cancer that had been surgically resected 8 years earlier, dementia, and hypertension. His current medications included docusate, multivitamins, tamsulosin, and ibuprofen.

The patient’s vital signs were within normal limits. He had pink urticarial plaques over his posterior trunk and proximal thighs (Figure 1). A shallow ulcer in the perianal area measured 3 cm² and had nonpurulent yellow slough (Figure 2). He appeared somewhat cachectic and had a well-healed thoracic surgical scar. The remainder of his examination was unremarkable.