Photosensitivity in the Elderly: Think of Protoporphyria

Considering the first report in the literature of a patient with late-onset X-linked dominant protoporphyria

Erythropoietic protoporphyria (EPP) is an uncommon photosensitivity usually produced by an inactivating germline mutation affecting ferrochelatase, the last enzyme in the heme biosynthetic pathway. Free protoporphyrin accumulates in erythrocytes, causing burning and stinging sensations a few minutes after sun exposure. The disease usually becomes apparent in childhood. Many features of EPP are present in X-linked dominant protoporphyria (XLDPP), a disease caused by a gain-of-function mutation in the gene that encodes 5-aminolevulinate synthase 2 (ALAS2), the first step in heme biosynthesis. The result is a buildup of zinc protoporphyrin in red blood cells and photosensitivity manifested by burning and stinging.

The authors describe an 89-yea…

Reviewing Author

Craig A. Elmets, MD

Disclosures

Consultant / Advisory board Astellas Pharmaceuticals

EquityVaxin

Grant / Research support NIH; NIH/NCI; Veteran’s Administration; Ferndale Laboratories; Kyowa Hakko Kirin Pharma, Inc.

Editorial boards Cancer Prevention Research; Photodermatology, Photoimmunology, & Photomedicine; UpToDate; eMedicine; Journal of Dermatological Sciences; JAMA Dermatology

Leadership positions in professional societies American Academy of Dermatology (Vice Chair, Committee on Science and Research); Photomedicine Society (Board of Directors)