Knuckle pads in Adult
In children and young adults, knuckle pads may be idiopathic, sporadic, familial, or associated with an inherited condition. There is an autosomal dominant condition composed of knuckle pads, total leukonychia, and sensorineural and conductive hearing loss (Bart-Pumphrey syndrome). Another condition in which knuckle pads are a component is autosomal dominant epidermolytic palmoplantar keratoderma with a mutation in keratin 9. Other associations include acrokeratoelastoidosis costa, keratoderma hereditaria mutilans, and pseudoxanthoma elasticum.
In older patients, knuckle pads may be associated with irreducible flexion contractures of one or more fingers, such as Dupuytren contracture and camptodactyly (permanent flexion of one or more finger joints). Other fibrosing disorders that may be associated with knuckle pads include Peyronie disease and Ledderhose disease.
Secondary (acquired) knuckle pads are thought to result from frequent trauma or knuckle-cracking. Any skin site that is subjected to constant friction or pressure may develop lesions that resemble knuckle pads. In these cases, the lesions are termed helodermas, subcutaneous fibromas, tylositas articuli, or discrete keratodermas. Secondary knuckle pads commonly occur in patients with obsessive-compulsive disorder who apply frequent trauma ("chewing pads"); bulimic patients who traumatize their fingers as a result of inducing emesis; manual workers whose hands are subject to persistent trauma; and athletes, including football players, surfers ("surfer nodules"), boxers, and other sports ("athlete's nodules").
M72.1 – Knuckle pads
16687001 – Knuckle pads
Differential Diagnosis & Pitfalls