Clinical and dermoscopic changes of acquired melanocytic nevi of patients treated with afamelanotide.

Background: Afamelanotide (AFA) is a synthetic analogue of α-melanocyte-stimulating hormone that is approved for the treatment of patients affected by erythropoietic protoporphyria (EPP). AFA induces a "sun free" tanning and changes of acquired melanocytic nevi (AMN) that are generically described as "darkening".

Objectives: To assess clinical and dermoscopic AMN changes during AFA treatment.

Methods: Adult EPP patients treated with two AFA implants 50 days apart were enrolled. They underwent a clinical and dermoscopic examination of all AMN at baseline (T0), and after 5 (T1) and 12 (T2) months from the first AFA implant. The general pattern, symmetry, number, and size of pigmented globules, morphology of the pigment network, and dermoscopic melanoma features were assessed.

Results: Fifteen patients were enrolled with 103 AMN. At T1 all reticular and 2-component AMN showed a focal network thickening that returned to baseline by T2. The increase of globules' number was observed at T1 but not at T2. The difference in number was not influenced by patients' age or phototype. Dermoscopic changes suggestive of malignancy were never seen. The development of new AMN was never registered.

Conclusions: AFA treatment induces reversible changes of AMN dermoscopic morphology without findings suggestive of malignant transformation and it does not stimulate the development of new AMN.