Hereditary focal palmoplantar keratoderma

PPK striata/areata type

Hereditary painful callosities

• Autosomal dominant inheritance

• DOES NOT affect organs other than the skin

• Small areas of skin thickening on palms and soles in childhood

• ‘Striate’ type: thick lines (particularly on palms or fingers)

• ‘Areata’ type: circles (particularly on soles of the feet)

• In most cases, mixed striate and areata thickenings

• May resemble corns on the soles of the feet

• The variant, hereditary painful callosities, affect only the feet

Howel-Evans syndrome

• Autosomal dominant inheritance

• Also called tylosis

• Childhood onset of focal keratoderma

• Oesophageal cancer in middle age

• White areas may be seen inside the mouth (leukokeratosis)

Richner-Hanhart syndrome

• Autosomal recessive inheritance

• Due to an enzyme deficiency (tyrosinaemia)

• Characterised by ulcers on the eye and dislike of bright light in the first year of life

• Focal keratoderma in late childhood or adolescence

• Most children have an intellectual disability

• Restriction of phenylalanine and tyrosine in the diet is required to improve symptoms and may prevent the progression of an intellectual disability

Pachyonychia congenita

• Several types exist with autosomal dominant inheritance

• Characterised by thickened wedge-shaped nails

• Palmoplantar keratoderma tends to be focal

• The classification depends on which keratin gene is mutated

Striate PPK with woolly hair and dilated cardiomyopathy

• Several types exist with autosomal recessive inheritance, including Naxos disease

• Coarse ‘woolly’ hair from birth

• Focal keratoderma develops in infancy

• Heart disease develops in adolescence

• May result in clubbing of the nails

• Blistering of the skin may occur