Erosive pustular dermatosis of the scalp: challenges and solutions.

Erosive pustular dermatosis of the scalp is a rare chronic inflammatory disorder defined. It usually affects elderly people and is characterized by extensive pustular lesions, erosions, and crusts located on the scalp. The pathogenesis of this disease is not completely understood, but a known predisposing factor is skin trauma. Autoimmune disorders including rheumatoid arthritis, autoimmune hepatitis, Hashimoto thyroiditis, and Takayasu aortitis are associated diseases reported. The clinical examination reveals erythema, erosions, crusts, follicular pustules, and in advanced stages, scarring alopecia. A scalp biopsy is recommended but not specific, founding epidermal atrophy, focal erosions, and a mixed inflammatory infiltrate consisting of neutrophils, lymphocytes, and plasma cells. Bacterial cultures, fungal and viral stains are not necessary and are usually negative. . Topical high-potency corticosteroids, retinoids, calcipotriol, dapsone, and topical tacrolimus are reported treatments, while photodynamic therapy has been effective in some patients, but has induced the disease in others. All the findings are suggestive but not specific, so it is an excluding diagnosis. The combination of predisposing factors is very important for a correct diagnosis, such as elderly age, sun-damaged skin, presence of androgenetic alopecia, together with clinical manifestations, non-specific histology and laboratory investigations negative for other disease. In our opinion, this scalp disease is a challenge for the dermatologist. We review all the literature to better define the possible solutions in case of suspected erosive pustular dermatosis of the scalp.