Acta Dermato-Venereologica 99-12CompleteContent | Page 38

1195 SHORT COMMUNICATION Dominant Dystrophic Epidermolysis Bullosa Pruriginosa Responding to Naltrexone Treatment Kristine Appel Uldall PALLESEN 1,2 , Kim Hein LINDAHL 3 and Anette BYGUM 1,2 Department of Dermatology and Allergy Centre, Odense University Hospital, DK-5000 Odense, 2 Clinical Institute, University of Southern Denmark, and 3 Department of Pathology, Vejle Hospital, Vejle, Denmark. E-mail: [email protected] 1 Accepted Aug 26, 2019; E-published Aug 27, 2019 Dominant dystrophic epidermolysis bullosa pruriginosa (DDEB-Pr) is a rare subtype of dystrophic epidermo- lysis bullosa (DEB). The disease was first proposed by McGrath in 1994 and is caused by mutations in the COL7A1 gene, which encodes type VII collagen (1, 2). The skin is characterized by bullae and erosions loca- ted on the extensor sites of the extremities from early childhood. Patients experience intense pruritus and other manifestations, such as papules, nodules, scarring and nail dystrophy in adulthood (3). We report here a case of DDEB-Pr with a clinical response to naltrexone treatment. a CASE REPORTS Case 1 A 40-year-old man presented with a history of pruritic skin lesions on the extensor sides of the lower extremities since his teenage years. Multiple, excoriated, infiltrated, hypertrophic linear and nodular elements were seen sym- metrically on the forearms, shins and feet. Other findings included scars and toenail dystrophy. No skin blistering was observed during childhood or in adult life, and the patient was not able to cause blisters by rubbing. His mucosa, teeth and hair were normal. A punch skin biopsy was performed in 1988 and was originally described as a folliculitis. The HE-stained slide was found in our archive and reviewed retrospectively in December 2018. Standard histology showed a slightly acanthotic multi-layer squamous epi­thelium with a cell- poor subepidermal blister and hyperkeratosis. There was sparse fibrosis in the underlying papillary dermis. No inflammatory cells were found in the blister and only a few lymphocytes in the papillary dermis. No milia were present. No specific signs of folliculitis could be found. Collagen IV staining was performed and collagen IV was found in the roof of the blister. The changes were consistent with the expected findings in DEB. Further subdivision of the clinical subtypes was not possible based on routine histology specimens. In adulthood a genetic investigation revealed a muta- tion in the COL7A1 gene: c.6846G>C (p.(Leu2282=)). Local treatment with potent topical corticosteroid and potassium permanganate were tried without convincing effect. Naltrexone treatment was started at a dose of 50 mg once daily since pruritus was the main complaint. The itch was reduced and the patient showed marked b Fig. 1. Skin manifestations in Case 1. (a) Before naltrexone treatment and (b) during treatment. clinical improvement in the lesions located on the lower legs after 3 months treatment with naltrexone and use of bandages (Fig. 1). The treatment was continued for a total of 11 months and no side-effects occurred. Case 2 The father of the index case was also known with clinical signs of DDEB-Pr since the age of 10 years. He showed multiple, hypertrophic linear and nodular lesions on the extensor surfaces of the extremities. The intense pruritus was reduced by a daily bath in the sea. He had toenail dystrophy (Fig. 2, right). Case 3 The 10-year-old son of the index case was suspected to have DDEB-Pr due to a newly developed tendency of trauma-induced ulcerations on his legs. The genetic investigation revealed the same mutation in the COL7A1 gene: c.6846G>C (p.(Leu2282=)). He had no pruritus or toenail dystrophy (Fig. 2). This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2019 Acta Dermato-Venereologica. doi: 10.2340/00015555-3304 Acta Derm Venereol 2019; 99: 1195–1196