Table 2.

Knuckle pads in various dermatoses

Knuckle pads	Associated disorders
Inherited disorders	Idiopathic (familial and sporadic)
	Associated with inherited palmoplantar keratodermas
	Epidermolytic palmoplantar keratoderma
	Loricrin keratoderma
	Mal de Meleda
	Gamborg-Nielsen palmoplantar keratoderma
	Vohwinkel syndrome
	Bart-Pumphrey syndrome
	Palmoplantar keratoderma and deafness syndrome
	Striate palmoplantar keratoderma
	Associated with other inherited disorders
	Camptodactyly
	Acrokeratoelastoidosis
	Keratosis punctata of plamar creases
	Pseudoxanthoma elasticum
	Peeling skin, leukonychia, acral keratoses, cheilitis and knuckle pads (PLACK) syndrome
Acquired disorders	Associated with fibromatosis
	Peyronie’s disease
	Ledderhose disease
	Dupuytren’s contracture
	Polyfibromatosis syndrome
	Pachydermodactyly
	Associated with other disorders
	Seborrhoeic dermatitis
	Finger clubbing
	Oral leukoplakia
	Glossitis
	Vitamin A deficiency
	Esophageal cancer
	Iatrogenic
	Phenytoin treatment
	Traumatic or friction associated (pseudo-knuckle pads)
	Occupational: In carpet layers, tailors, sheep shearers, live chicken hangers, pillar knockers
	Athletes: Boxers, surfers, football players, other sports (athletes nodules)
	Bulimia nervosa (Russel’s sign)
	Obsessive compulsive disorders (chewing pads, habitual knuckle cracking)