Porokeratosis ptychotropica responding to photodynamic therapy: An alternative treatment for a refractory disease

Abstract
Background Porokeratosis ptychotropica (PP) is a rare variant of porokeratosis with a special predisposition to affect body folds, particularly the intergluteal cleft. This disease is resistant to most topical and systemic treatments, as shown in the review of the literature we provide here. Itching and discomfort are often a difficult problem to solve. Patients and Methods Two patients with PP that had not responded to multiple topical treatments were treated with photodynamic therapy (PDT). Changes in plaque size, thickness and symptoms were assessed after treatment. Results Pruritus disappearance was observed in both patients after treatment with PDT. Partial clearance of the plaques was observed in one case. In the other case, a moderate clearance of hyperkeratosis was observed, although the size of the lesions persisted unchanged. Conclusions PDT seems to be a good therapeutic alternative in the treatment of PP, as it can provide symptomatic relief and clinical improvement of the lesions. However, it does not appear to be a curative treatment. Moreover, long‐term response is still unknown.