plantarkeratodermie

Plantarkeratodermie, also known as plantar keratoderma, is a group of skin disorders characterized by thickening of the stratum corneum on the soles of the feet. In some forms the palms are involved as well, a combination referred to as palmoplantar keratoderma. The condition can be diffuse, focal, or punctate, and may be accompanied by fissures, pain, and reduced ability to walk.

Plantarkeratodermie can be hereditary or acquired. Hereditary forms are usually autosomal dominant and arise from mutations in keratin genes and other proteins involved in skin structure and keratinocyte function (for example KRT9, KRT1, KRT6A, KRT16, KRT17). Acquired forms may be related to chronic eczema, psoriasis, fungal infections, arsenic exposure, or metabolic conditions, and may occur without a family history.

Clinical features depend on the subtype. Diffuse plantar keratoderma presents with widespread thickening of the sole; focal forms produce localized plaques at weight-bearing areas; punctate keratoderma shows small, dense keratotic papules. Pain, scaling, fissuring, and tenderness can impair walking, and secondary infections may occur.

Diagnosis is based on clinical evaluation and history, including family history. Skin biopsy can show hyperkeratosis with varying degrees of acanthosis; genetic testing may identify specific pathogenic variants in hereditary cases. Exclusion of infectious or inflammatory mimics is common.

Management aims to soften and reduce thickening and prevent fissures. Regular emollients and keratolytics (such as urea or salicylic acid) are first-line. Topical corticosteroids may help if inflammation is present. Severe or widespread cases may require systemic retinoids under specialist supervision, along with protective footwear and, when appropriate, physical debridement. Prognosis varies by subtype and severity, with lifelong management in many hereditary cases.