Pathogenesis (development of disease)
Clavus is caused by chronic pressure or friction on the affected area of skin near the bone, resulting in hyperkeratosis (excessive keratinization of the skin).
Etiology (causes)
Biographic causes
- Genetic burden from parents, grandparents: e.g., hereditary hyperkeratosis (excessive keratinization of the skin that is genetically determined), gout (see gout below)
Behavioral causes
- Wearing inappropriate footwear (e.g., too tight, high heels).
- Dry skin
- Chemical irritants
Disease-related causes
Congenital malformations, deformities, and chromosomal abnormalities (Q00-Q99).
- Hereditary hyperkeratoses
- Foot abnormalities – in particular flat foot and plantar fasciitis (pes transversoplanus).
- Toe deformities, congenital
Skin and subcutaneous (L00-L99)
- Nail changes, unspecified, may result in subungual or clavi in the nail fold
Musculoskeletal system and connective tissue (M00-M99).
- Exostoses (bony outgrowth).
- Gout (arthritis urica/uric acid-related joint inflammation or tophic gout)/hyperuricemia (elevation of uric acid levels in the blood)
- Hallux valgus (hammer toe)
- Toe deformities, acquired
Laboratory diagnoses – laboratory parameters that are considered independent risk factors.
- Hyperuricemia (elevation of uric acid levels in the blood).
Other causes
- Condition after joint fusion
- Condition after radiotherapy
