BI34 A case of trichodysplasia spinulosa: a rare cutaneous eruption in immunosuppressed patients

Abstract

Trichodysplasia spinulosa (TS) is a rare disease in people with immunosuppression, characterized by a papular, follicular rash with spiny keratosis (‘spicules’) and nonscarring alopecia. This condition is unique to patients with trichodysplasia spinulosa-­associated polyomavirus (TSPyV) in the setting of immunosuppression. We present a case of TS highlighting the correlation between its clinical, histological and polymerase chain reaction (PCR) findings. A 51-year-old woman, 2 years after live-related renal transplantation, presented with progressive widespread follicular lesions on the face and limbs with eyebrow alopecia. The lesions began 1 year after transplantation and were asymptomatic, but worsened following a change in immunosuppression from mycophenolate mofetil (discontinued after 11 months due to leucopenia and gastrointestinal intolerance) to azathioprine, which had been continued for the last year. Clinical examination revealed 1–2-mm folliculocentric papules with white keratin spicules on the nose, arms and legs, along with eyebrow alopecia. She had been misdiagnosed by her renal physician and general practitioner as having seborrhoeic dermatitis, which delayed dermatology referral by 1 year. Histopathological examination of biopsies from the left forearm and nose demonstrated dilated hair follicles with keratin plugging, dystrophic inner root sheath epithelium, and large eosinophilic trichohyalin granules. Viral cytopathic changes were noted, including smudged hyperchromatic nuclei with intracytoplasmic inclusions. PCR testing on both specimens was positive for TSPyV, confirming the diagnosis of TS. Treatment with oral valganciclovir 450 mg twice daily, keratolytic emollients and adapalene was initiated. At the 2-month follow-up the facial lesions had improved, with minimal response on the limbs. TS is a rare TSPyV-associated condition, with approximately 60 cases reported, predominantly in solid organ transplant recipients. Diagnosis relies on characteristic clinical features supported by histopathology and TSPyV PCR. No standardized treatment exists; reported therapies include topical cidofovir 3%, oral valganciclovir and reduced immunosuppression. Awareness of TS is essential for early diagnosis and management in immunosuppressed patients.