// Workers AI · dad joke modeWhat did nummular dermatitis say? I'm feeling a little coin-sized stress.
| Nummular dermatitis | |
|---|---|
| Other names | Discoid dermatitis, Discoid eczema, Microbial eczema, Nummular eczema, Nummular neurodermatitis |
 | |
| Lesions visible on outer thigh | |
| Specialty | Dermatology |
| Differential diagnosis | Dermatophytosis (Ringworm) |
Nummular dermatitis (commonly known as nummular eczema or discoid eczema) is one of the many forms of dermatitis.[1] It is characterized by round or oval-shaped itchy lesions.[2] The name comes from the Latin word "nummus," which means "coin."
Signs and symptoms
[edit]Nummular dermatitis is characterized by chronic or relapsing itchy coin-sized ovoid-shaped red plaques.[3][4] They can occur on the trunk, limbs, face, and hands.[1][2][5]
Causes
[edit]Many contact sensitizers or irritants are known to cause contact dermatitis superimposed on nummular dermatitis. Studies have implicated nickel, cobalt, chromate, and fragrance as likely culprits.[6][7] Xerosis, or dehydration of skin is also a likely cause.[8] Infection with Staphylococcus aureus bacteria or Candida albicans may also play a role.[8]
Diagnosis
[edit]Diagnosis of nummular dermatitis is largely via clinical observation. Biopsies are typically not necessary, and cannot be used to rule out other atopic dermatitis or other eczemas.[9][10] However, patch testing may be employed to rule out irritants (contact dermatitis) as a cause.[6][11] In children, nummular dermatitis is commonly confused with tinea corporis.[8]
Treatment
[edit]One of the keys to treatment and prevention involves keeping the skin hydrated. If the condition flares up, a common treatment involves the application of topical corticosteroids.[12] Oral antihistamines may help lessen itching.[13] Avoidance of irritants is a common strategy. More severe cases sometimes respond to ultraviolet light treatment. If the condition occurs only during the sun-less winter months then vitamin D supplement might be an effective treatment.[citation needed][14]
Epidemiology
[edit]The prevalence of nummular dermatitis in the United States is approximately 2 per 1,000.[15] It is considered a disease of adulthood, for it is rare in children.[16]
See also
[edit]References
[edit]- 1 2 Cowan MA (1961-01-01). "Nummular eczema. A review, follow-up and analysis of a series of 325 cases". Acta Dermato-Venereologica. 41: 453–460. PMID 13881857.
- 1 2 Weidman AI, Sawicky HH (January 1956). "Nummular eczema; review of the literature: survey of 516 case records and follow-up of 125 patients". A.M.A. Archives of Dermatology. 73 (1): 58–65. doi:10.1001/archderm.1956.01550010060006. PMID 13275125.
- ↑ Adachi A, Horikawa T, Takashima T, Ichihashi M (August 2000). "Mercury-induced nummular dermatitis". Journal of the American Academy of Dermatology. 43 (2 Pt 2): 383–385. doi:10.1067/mjd.2000.102457. PMID 10901730.
- ↑ Rollins TG (October 1968). "From xerosis to nummular dermatitis. The dehydration dermatosis". JAMA. 206 (3): 637. doi:10.1001/jama.1968.03150030093022. PMID 5695586.
- ↑ Perry AD, Trafeli JP (2009-05-01). "Hand dermatitis: review of etiology, diagnosis, and treatment". Journal of the American Board of Family Medicine. 22 (3): 325–330. doi:10.3122/jabfm.2009.03.080118. PMID 19429739.
- 1 2 Khurana S, Jain VK, Aggarwal K, Gupta S (December 2002). "Patch testing in discoid eczema". The Journal of Dermatology. 29 (12): 763–767. doi:10.1111/j.1346-8138.2002.tb00219.x. PMID 12532040. S2CID 43205871.
- ↑ Bonamonte D, Foti C, Vestita M, Ranieri LD, Angelini G (2012). "Nummular eczema and contact allergy: a retrospective study". Dermatitis. 23 (4): 153–157. doi:10.1097/der.0b013e318260d5a0. PMID 22828253. S2CID 446758.
- 1 2 3 Williams HC (June 2005). "Clinical practice. Atopic dermatitis". The New England Journal of Medicine. 352 (22): 2314–2324. doi:10.1056/NEJMcp042803. PMID 15930422.
- ↑ Kulthanan K, Samutrapong P, Jiamton S, Tuchinda P (December 2007). "Adult-onset atopic dermatitis: a cross-sectional study of natural history and clinical manifestation". Asian Pacific Journal of Allergy and Immunology. 25 (4): 207–214. PMID 18402293.
- ↑ Julián-Gónzalez RE, Orozco-Covarrubias L, Durán-McKinster C, Palacios-Lopez C, Ruiz-Maldonado R, Sáez-de-Ocariz M (2012-09-01). "Less common clinical manifestations of atopic dermatitis: prevalence by age". Pediatric Dermatology. 29 (5): 580–583. doi:10.1111/j.1525-1470.2012.01739.x. PMID 22469300. S2CID 5339404.
- ↑ Krupa Shankar DS, Shrestha S (2005-11-01). "Relevance of patch testing in patients with nummular dermatitis". Indian Journal of Dermatology, Venereology and Leprology. 71 (6): 406–408. doi:10.4103/0378-6323.18945. hdl:1807/5587. PMID 16394482.
- ↑ "Nummular Eczema: vs Ringworm, Causes, Symptoms, Treatment". Cleveland Clinic. Archived from the original on 2026-02-22. Retrieved 2026-02-22.
- ↑ Robinson, Carolyn A.; Love, Lauren W.; Saleh, Haitham M.; Farci, Fabiola (2025), "Nummular Dermatitis", StatPearls, Treasure Island (FL): StatPearls Publishing, PMID 33351436, retrieved 2026-02-22
- ↑ "Drug-induced nummular dermatitis". DermNet®. 2023-10-26. Retrieved 2026-01-22.
- ↑ Johnson ML, Roberts J (1977-01-01). "Prevalence of dermatological disease among persons 1-74 years of age: United States". ADV Data Natl CTR Health Statistics.
- ↑ Krol A, Krafchik B (2006-03-01). "The differential diagnosis of atopic dermatitis in childhood". Dermatologic Therapy. 19 (2): 73–82. doi:10.1111/j.1529-8019.2006.00058.x. PMID 16669989. S2CID 42426282.