Efficacy of the Radiotherapy on Darier’s Disease: An Indirect Evidence

Darier’s disease (DD) is an autosomal dominant dermatosis characterized by hyperkeratotic papules that are mainly located in the seborrheic areas and pushups, handheld wells, and nails. The disease often appears at a young age, typically by the third decade, with no sex predilection. There is currently no standard therapy and there are usually topical palliative therapies. We present the case of an affected 42-year-old woman treated with radiation therapy for early breast cancer. Before the radiotherapy, the patient showed hyperkeratotic, brownish papules extending in a linear pattern for the neck to the abdomen, especially on both breasts and inframammary area. During the radiation, she developed grade 1 to 2 dermatitis in the irradiated area. At a followup of 6 months, the patient has no skin lesions in the irradiated zone. This report suggests that the radiotherapy is not contraindicated and may indeed be effective in local control of skin lesions in DD. 1. Introduction Darier’s disease (DD), also known as Darier-White disease [1], Dyskeratosis follicularis [2], and keratosis follicularis [3], is an autosomal dominant dermatosis characterized by hyperkeratotic papules that are particularly dense in the seborrheic areas and flexures, palmar pits, and nail dystrophy. Darier’s disease affects both men and women and is not contagious. The disease often appears at a young age, typically by the third decade, with no sex predilection. It is considered a rare disease because its prevalence in the world is estimated to be between 1？:？30.000 and 1？:？100.000. It most commonly affects the chest, neck, back, ears, and groin but may involve other body areas. The rash associated with Darier’s disease often has a distinct odour. Palms and soles may become thickened, and intraoral papules can be found. Finger nails become fragile, and this helps in diagnosis of the disease. The rash can be aggravated by heat, humidity, and exposure to sunlight. In some cases, sunlight makes it better, especially in the forehead. About etiopathogenesis, it was reported that mutations in the gene AT-P2A2, located on chromosome 12q23-24.1, cause DD [4]. It seems likely that the mutation interferes with the normal internal calcium signalling that regulates processes such as cell proliferation, differentiation, and adhesion between keratinocytes [5]. This defect in intracellular calcium regulation justifies histological features, including dyskeratosis, suprabasal acantholysis, and papillomatosis. DD is difficult to treat. A variety of palliative medical therapies exist as topical