Trichodysplasia spinulosa mimicking lichen nitidus in a renal transplant patient

Abstract

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.

Pediatric trichodysplasia spinulosa: A report of 2 cases and review of the literature

“…All patients presented with predominately centrofacial folliculocentric papules with keratinaceous spines. Twelve of the 19 cases demonstrated generalized involvement including the trunk and extremities 2,4,7,9‐15,18 . Lateral eyebrow alopecia and less commonly eyelash alopecia were reported as well 2,7,8,11,12,17,20 .…”

“…Lymphoblastic leukemia was the most common underlying diagnosis, reported in seven patients 7‐13 . Renal transplant was the second most common, reported in five patients 4,14‐16 . Other underlying diagnoses included heart transplant, colon transplant, lung transplant, and multiorgan transplant 2,5,17‐20 .…”

“…Immunosuppressive medications included tacrolimus, mycophenolate mofetil, systemic steroids, vincristine, methotrexate, cytarabine, cyclophosphamide, mercaptopurine, and sirolimus. The most commonly encountered combination was tacrolimus, mycophenolate mofetil, and systemic steroids, used in six patients 2,4,14‐16,19 …”

Recent developments in trichodysplasia spinulosa disease

“…In 2019, a kidney transplant patient presented with slightly pruritic papules spread diffusely over most of her body in the absence of other generalized symptoms, with some facial papules demonstrating subtle spiny projections resembling lichen nitidus ( Table 1). 41 Lichen nitidus is a common, benign skin condition that is character- with high average viral loads in a study. 42 Routine testing with PCR assays, gene-sequencing studies, immunohistochemical stains, or electron microscopy is not necessary in all cases since routine histological staining can be sufficient to make the diagnosis in classic clinical presentations.…”

“…5 We provide further evidence of this relationship, as 10 cases reviewed in Table 1 were exposed to mycophenolate mofetil before TS development, and reducing mofetil treatment showed significant improvement in TS disease in 5 of these patients (Table 1). 6,8,11,27,41,49,[51][52][53] Thus, the mechanistic link between mycophenolate mofetil and TS disease development should be further investigated.…”