Knuckle pads

Knuckle pads
SpecialtyRheumatology Edit this on Wikidata

Knuckle pads, also known as heloderma, meaning similar to the skin of the Gila monster lizard for which it is named, are circumscribed, keratotic, fibrous growths over the dorsa of the interphalangeal joints. They are described as well-defined, round, plaque-like, fibrous thickening that may develop at any age, and grow to be 10 to 15mm in diameter in the course of a few weeks or months, then go away over time.

Knuckle pads are sometimes associated with Dupuytren's contracture and camptodactyly,: 595  and histologically, the lesions are fibromas.: 595  Knuckle pads are generally non-responsive to treatment, including corticosteroids, and tend to recur after surgery; however, there has been some effectiveness with intralesional fluorouracil.

Signs and symptoms

Knuckle pads are benign subcutaneous fibrotic nodules that are seen in the finger joints and/or the extensor area of the foot. From a clinical perspective, these are well-defined, non-compressible, freely moveable lesions that resemble warts and primarily affect the dorsal portion of the proximal interphalangeal (PIP) and, less frequently, the metacarpophalangeal (MCP) joints. Knuckle pads are often asymptomatic, painless, and progressive in their growth, reaching their final size of up to 40 mm in diameter. They also do not cause any functional impact on the joints, such as decreased flexibility or altered tendons.

Causes

Since the pathogenesis is yet unclear, knuckle pads are usually idiopathic. They are a fibromatous illness characterized by fibroblast growth leading to fibrosis.

Acrokeratoelastoidosis of Costa, camptodactyly, epidermolytic palmoplantar keratoderma, Dupuytren's disease, plantar fibromatosis (Ledderhose's disease), and Bart-Pumphrey syndrome are among the hereditary syndromes in which knuckle pads may be observed.

Knuckle pads can also be acquired subsequent to trauma. In sports like boxers and swimmers, as well as in some occupations like carpet layers, secondary knuckle pads are well-documented. Knuckle pads have also been reported in individuals suffering from obsessive-compulsive disorder and bulimia nervosa. Individuals with excoriation disorder often bite their knuckles to relieve stress/tension.

Diagnosis

The diagnosis of knuckle pads is clinical.  The differential diagnosis includes retained foreign objects, neurofibromas, rheumatoid nodules, gouty tophi, warts, xanthomas, synovial cysts, and Bouchards and Heberdens nodes. When a diagnosis is unclear, plain radiographs, histology (if sonography is not conclusive), and ultrasound improve the information-gathering process and lower the possibility of a misdiagnosis.

Knuckle pads show up as noncompressible, dome-shaped, hypoechoic nodules on ultrasonography and as peripheral or nonexistent vascularization on Doppler analysis. On histology, the pads show enhanced proliferation of (myo-)fibroblasts, which is frequently linked to hyperkeratosis.

Treatment

In the lack of targeted and efficacious treatments, a stressful wait-and-see strategy is typically advised. Surgery has also been utilized, though typically without producing a change in appearance. Potential adverse effects include scars, keloids, post-operative loss of joint flexibility, and recurrences.

A small number of treatments have shown promise recently,[when?] but they are frequently moderately to highly invasive and are primarily based on case reports. Intralesional triamcinolone, fluorouracil, cantharidin-podophyllotoxin-salicylic acid, and topical high-dose salicylic acid and urea have all been successfully applied, according to certain authors.

If the knuckle pads are caused by repetitive trauma, they should heal in a couple of months after the trauma ceases.

See also

References

  1. ↑ Mackey, SL; Cobb, MW (1994). "Knuckle pads". Cutis. 54 (3): 159–160. PMID 7813233.
  2. 1 2 3 James, WD; Berger, TG; Elston, DM (2005). Andrews' Diseases of the Skin: Clinical Dermatology (11th ed.). Saunders. p. 595. ISBN 0-7216-2921-0.
  3. 1 2 Mikkelsen, Otto (October 1, 1977). "Knuckle Pads in Dupuytren's Disease". Journal of Hand Surgery (European Volume). 9 (3): 301–305. doi:10.1016/S0072-968X(77)80121-6. PMID 608634. S2CID 7999131. Retrieved 27 October 2020.
  4. 1 2 Meinecke, R; Lagier, R (September 1975). "Pathology of "knuckle pads"". Virchows Archiv. 365 (3): 185–191. doi:10.1007/BF00434037. PMID 804749. S2CID 4518671. Retrieved 27 October 2020.
  5. 1 2 3 4 5 Weiss, E; Amini, S (2007). "A Novel Treatment for Knuckle Pads With Intralesional Fluorouracil". Arch Dermatol. 143 (11): 1447–1462. doi:10.1001/archderm.143.11.1458. PMID 18025384.
  6. 1 2 Herold, Manfred; Russe-Wilflingseder, Katharina; Longo, Leonardo (2010). Knuckle Pads—A common problem but good to treat by Laser. AIP Conference Proceedings. pp. 179–183. doi:10.1063/1.3453778.
  7. 1 2 3 4 5 Tamborrini, Giorgio; Gengenbacher, Michael; Bianchi, Stefano (2012-12-30). "Knuckle pads – a rare finding". Journal of Ultrasonography. 12 (51). Medical Communications Sp. z.o.o.: 493–498. doi:10.15557/jou.2012.0037. ISSN 2084-8404. PMC 4603232. PMID 26672439.
  8. 1 2 3 Hasbún, Catalina; Sandoval, Mauricio; Curi, Maximiliano (2019-03-18). "A novel treatment for idiopathic knuckle pads with cantharidin-podophylotoxin-salicylic acid". Pediatric Dermatology. 36 (4). Wiley: 544–545. doi:10.1111/pde.13803. ISSN 0736-8046. PMID 30883856.
  9. 1 2 3 4 5 De Keersmaeker, Alexander; Vanhoenacker, Filip (2016-07-12). "Imaging Features of Knuckle Pads". Journal of the Belgian Society of Radiology. 100 (1). Ubiquity Press, Ltd.: 67. doi:10.5334/jbr-btr.1096. hdl:10067/1343460151162165141. ISSN 1780-2393. PMC 6102944. PMID 30151469.
  10. 1 2 Chandler, Zachary; Seamon, Kimberly; Ramsubeik, Karishma; Kaeley, Gurjit (2022). "A case of knuckle pad syndrome in a middle-aged man". Clinical Case Reports. 10 (12) e6740. Wiley. doi:10.1002/ccr3.6740. ISSN 2050-0904. PMC 9764040. PMID 36545555.
  11. ↑ Barrick, Carl; Moran, Joshua; Oram, Christian; Purcell, Stephen (2018). "Acrokeratoelastoidosis and knuckle pads coexisting in a child". Cutis. 102 (5): 344–346. ISSN 2326-6929. PMID 30566539.
  12. ↑ Kelenjian, Shinorik; Mattjie, Rebeca Assuncao; Franz, Regina; Biedermann, Tilo; Brockow, Knut (2019). "Clinical features and management of superficial fibromatoses". Journal der Deutschen Dermatologischen Gesellschaft. 17 (4): 393–397. doi:10.1111/ddg.13808. ISSN 1610-0387. PMID 30865379.
  13. ↑ Gönül, Müzeyyen; Gül, Ülker; Hizli, Pelin; Hizli, Ömer (2012). "A family of Bart-Pumphrey syndrome". Indian Journal of Dermatology, Venereology and Leprology. 78 (2). Scientific Scholar: 178–181. doi:10.4103/0378-6323.93636. ISSN 0378-6323. PMID 22421650.
  14. ↑ Dickens, Rio; Adams, Brian B.; Mutasim, Diya F. (2002). "Sports-related pads". International Journal of Dermatology. 41 (5). Wiley: 291–293. doi:10.1046/j.1365-4362.2002.01356_3.x. ISSN 0011-9059. PMID 12100708.
  15. ↑ Kanerva, L. (1998). "Knuckle pads from boxing". European Journal of Dermatology. 8 (5): 359–361. ISSN 1167-1122. PMID 9683870.
  16. ↑ Calikoğlu, Emel (2003). "Pseudo-knuckle pads: an unusual cutaneous sign of obsessive-compulsive disorder in an adolescent patient". The Turkish Journal of Pediatrics. 45 (4): 348–349. ISSN 0041-4301. PMID 14768804.
  17. ↑ Nenoff, Pietro; Woitek, Gerald (2011-06-23). "Knuckle Pads". New England Journal of Medicine. 364 (25). Massachusetts Medical Society: 2451. doi:10.1056/nejmicm1008915. ISSN 0028-4793. PMID 21696311.
  18. 1 2 CAROLI, A.; ZANASI, S.; MARCUZZI, A.; GUERRA, D.; CRISTIANI, G.; RONCHETTI, I. PASQUALI (1991). "Epidemiological and Structural Findings Supporting the Fibromatous Origin of Dorsal Knuckle Pads". Journal of Hand Surgery (European Volume). 16 (3). SAGE Publications: 258–262. doi:10.1016/0266-7681(91)90049-t. ISSN 0266-7681. PMID 1960489.
  19. ↑ Paller, Amy S. (1986-09-01). "Knuckle Pads in Children". Archives of Pediatrics & Adolescent Medicine. 140 (9). American Medical Association (AMA): 915–917. doi:10.1001/archpedi.1986.02140230085039. ISSN 1072-4710. PMID 2943155.
  20. ↑ Sogliani, Davide; Mura, Chiara; Tamborrini, Giorgio (2021-04-13). "Successful treatment of idiopathic knuckle pads with a combination of high-dose salicylic acid and urea topical keratolytics: A case report". Dermatology Reports. 13 (1). PAGEPress Publications: 9072. doi:10.4081/dr.2021.9072. ISSN 2036-7406. PMC 8139120. PMID 34040706.

Further reading