Trichodysplasia spinulosa (TS) is a rare cutaneous condition associated with the TSPyV and characterized by skin‐colored, folliculocentric papules with keratin spicule formation. TS is seen almost exclusively in immunosuppressed individuals, often presenting in patients with a history of solid organ transplantation or chemotherapy for a lymphoreticular malignancy. We report a case of widespread TS in a 9‐year‐old girl with a history of renal transplantation complicated by BK viremia, which is also caused by a polyomavirus, BKPyV. The clinical presentation of TS in this case morphologically resembled the more common, harmless skin condition known as “lichen nitidus,” and was more extensive than expected for TS, creating a diagnostic challenge. This case illustrates an important presentation of severe TS of which transplant teams, oncologists, primary care providers, and dermatologists should be aware.

Janus kinase (JAK) inhibitors are being prescribed with increasing regularity in dermatology. We report on a patient who initiated treatment with tofacitinib for refractory erythema elevatum diutinum and subsequently developed a novel cutaneous outbreak characterized by firm violaceous papules on the trunk and extremities along with conjunctival injection and periorbital inflammation. Biopsy of affected tissue from both the cutaneous and ophthalmologic sources demonstrated increased numbers of CD30 + large atypical cells amid a mixed inflammatory cell infiltrate, consistent with lymphomatoid papulosis. A review of the literature reveals a plausible mechanism for the induction of persistent JAK signaling in the presence of a JAK inhibitor. We discuss this mechanism in depth because it pertains to this patient and recommend continued vigilance with the use of these immunologic agents.