Hereditary polymorphic light eruption is a form of photosensitivity found in the American Indians of the central plains of Canada and the United States and in the Indians of Central and South America. The disorder has also been called familial actinic prurigo, solar dermatitis, and hydroa aestivale. In northern latitudes, skin lesions appear on exposed areas early in spring, become severe during the summer, and abate in the fall. Usually the disorder appears in childhood with eczematous crusted eruptions on the face and arms. Fissured, crusted exudative cheilitis develops on the lips, especially the lower lip. The dorsum of the hands, the laterodorsal aspects of the forearms, and the lower half of the arms often show excoriated papular and nodular lesions. Children frequently have complicating pyoderma. Adults usually exhibit an erythematous plaquelike eruption on the face and other exposed areas. The disease is more severe in children than in adults. Glomerulonephritis can follow streptococcal pyoderma (summary by Fusaro and Johnson, 1980).

Chronic mucocutaneous candidiasis is characterized by recurrent or persistent infections of the skin, nails, and oral and genital mucosae with Candida albicans, and sometimes by staphylococcal skin infections (summary by Boisson et al., 2013). For a discussion of genetic heterogeneity of familial candidiasis, see CANDF1 (114580).

Combined immunodeficiency due to MALT1 deficiency is a rare, genetic form of primary immunodeficiency characterized by growth retardation, early recurrent pulmonary infections leading to bronchiectasis, inflammatory gastrointestinal disease, and other symptoms, such as rash, dermatitis, skin infections.

A rare genetic skin disease characterized by generalized skin peeling, leukonychia, acral punctate keratoses coalescing into focal keratoderma on the weight-bearing areas, angular cheilitis and knuckle pads with multiple hyperkeratotic micropapules. The skin appears dry and scaly with superficial exfoliation and underlying erythema. Histopathologic examination of affected skin areas shows hyperkeratosis, acanthosis and intraepidermal clefting with irregular acantholysis. Additional systemic abnormalities are absent.

Olmsted syndrome-2 (OLMS2) is characterized by mutilating hyperkeratotic skin lesions, primarily on the palms and soles, but also extending onto dorsal surfaces of the hands and feet and distal extremities. The lesions are progressive, becoming thicker with verrucous fissures on the palms and soles over time. In addition, affected individuals exhibit perioral hyperkeratosis, and may have lesions around other orifices as well, such as the nostrils, perineum, and anus. Most patients also have hyperkeratotic nails and light-colored woolly hair (Duchatelet et al., 2019). Some patients may experience flexion contractures of the digits due to the severity of the keratoderma, and intractable pruritus and alopecia universalis have been observed (Dai et al., 2020). For a general phenotypic description and discussion of genetic heterogeneity of Olmsted disease, see OLMS1 (614594).