In Reply We appreciate the letter in response to our case report. We acknowledge the limitations in making a diagnosis of trichodysplasia spinulosa (TS) using only clinical and histologic findings.
Electron microscopy (EM) was attempted in our case, but the diagnostic area was exhausted. We want to emphasize that owing to our patient’s syndrome, he had undergone a multitude of procedures and imaging studies. Therefore, from a compassionate standpoint, and at the patient’s request, additional biopsies of the spiny facial lesions were not performed. Although virus was not confirmed, we believe that the clinical (central face, folliculocentric) and histologic (trichohyalin debris in inner root sheath cells) features of this case are very similar to those of virus-proven cases of TS, both in publication and presented at a recent American Society of Dermatopathology meeting.1,2 Other cases of targeted therapy–induced follicular hyperkeratosis do not demonstrate the same trichohyalin debris or inclusions.3
Richey JD, Katona T, Travers JB. Trichodysplasia Spinulosa in Gorlin Syndrome Treated With Vismodegib—Reply. JAMA Dermatol. 2015;151(4):459. doi:10.1001/jamadermatol.2014.4388