BP showed a mean incidence of 12.1 new cases per million people per year. Its incidence increased significantly after the age of 70 years, with a maximal value after the age of 90 years. The female/male ratio was 1.3. The age-standardized incidence of BP using the European population as reference was, however, lower, with 6.8 new cases per million people per year, reflecting the ageing of the Swiss population. In contrast, both PV and PF were less frequent. Their combined mean incidence was 0.6 new cases per million people per year. CONCLUSIONS; This is the first comprehensive prospective study analysing the incidence of autoimmune bullous diseases in an entire country. Our patient cohort is large enough to establish BP as the most frequent autoimmune bullous disease. Its incidence rate appears higher compared with other previous studies, most likely because of the demographic characteristics of the Swiss population. Nevertheless, based on its potentially misleading presentations, it is possible that the real incidence rate of BP is still underestimated. Based on its significant incidence in the elderly population, BP should deserve more public health concern.

SBF might be seen more frequently than has been described due to misinterpretation. Therefore primary syphilis should be included in the differential diagnosis of balanitis and balanoposthitis.

Reticulate pigmentation of the neck is a common finding in numerous genodermatoses and acquired diseases. As the neck is readily accessible to medical inspection, it may serve as a diagnostic window for various dermatoses. Several entities out of the spectrum of ectodermal dysplasia present with reticulate or mottled pigmentation on the upper trunk and neck. The most impressive genodermatoses with punctate and reticulate pigmentation affecting the neck are the Naegeli-Franceschetti-Jadassohn syndrome, dermatopathia pigmentosa reticularis and dyskeratosis congenita. Reticulate pigmented anomaly of the flexures and lentiginosis, disorders of cornification and related entities are further genodermatoses which may involve the neck. In our review we have integrated inherited dermatoses which do not obligatorily affect the neck but have been well documented to do so. Our work should give the clinician a checklist on genodermatoses which may produce reticulate and mottled pigmentation on the neck.

Balanitis is a descriptive diagnosis for a heterogeneous group of infectious or inflammatory dermatoses which have to be differentiated from malignant conditions. Balanitis is caused not only by Candida spp. and bacterial infections, including anaerobic bacteria: viral infections, parasites and other sexually transmitted infections (STI) also have to be considered. Lichen planus, psoriasis and contact dermatitis can characteristically lead to inflammatory conditions of the glans penis. In addition to a complete skin examination, a thorough patient history with respect to topically applied products and sexual behavior is essential. Infections must be treated and the glans penis should be kept dry. It is important to ensure a balanced genital hygiene in patients. As a last resort therapeutic circumcision can be considered for most forms of chronic balanitis.

Besides the inherited forms of mottled and reticulate pigmentation, a vast number of diseases and trigger mechanisms can lead to acquired pigmentation of the neck. Nonhereditary variants of reticulate and mottled pigmentation can affect the neck as a typical site and therefore may give a diagnostic clue or it can occur sporadically on the neck as well as on other sites. A well-known and important factor in the pathogenesis is exposure to sunlight. Sun-induced pigmentation often presents on the neck and may result from phototoxic, photoallergic and cumulative actinic damage. Frequent forms comprise berloque dermatitis, Riehl’s melanosis, poikiloderma of Civatte and tanning bed lentigines. Different infections may also lead to this distinct skin alteration as pediculosis capitis, pityriasis versicolor and syphilis II. Treatment-induced irregular pigmentations may occur after applications of topical agents (e.g. diphenylcyclopropenone), systemic medication (e.g. 5-fluorouracil, chlorpromazine), as a complication of laser resurfacing or as a chronic graft-versus-host reaction. Different neoplasms may also involve the neck. Widespread pigmented basal cell carcinoma, cutaneous T-cell lymphoma, syringolymphoid hyperplasia and histiocytic diseases may lead to reticulated pigmentation. Various other infrequent conditions as connective tissue diseases, malnutrition, lichen planus pigmentosus and others are summarized. The neck, a readily accessible site to medical inspection, may have an underestimated value for the diagnosis of different skin diseases.