Tinea nigra in Adult
Alerts and Notices
Synopsis

After contamination from an infected source (eg, soil, sand, waste, or wood), the mycosis infects the stratum corneum, resulting in a dark macule or patch as the fungal hyphae produce melanin. The incubation period is typically 10-15 days.
The most frequently affected populations are children and adolescents (children are more prone to exposure to the fungus); however, persons of any age may be affected.
Immunocompromised Patient Considerations
The fungus involved in causing infections of tinea nigra can lead to serious infections in immunocompromised patients. There is a risk of disseminated disease from superficial cutaneous fungal infections noted in transplant patients.
Codes
ICD10CM:B36.1 – Tinea nigra
SNOMEDCT:
186289000 – Tinea nigra
Look For
Subscription Required
Diagnostic Pearls
Subscription Required
Differential Diagnosis & Pitfalls
Single lesion:- Talon noir – Intracorneal hemorrhage, secondary to trauma.
- Acral melanocytic nevus – Presents with furrow or fibrillar pattern on dermoscopy, which is not seen in tinea nigra.
- Melanoma – Presents with irregular borders, color of different shades, expanding diameter; easily differentiated from tinea nigra using dermoscopy. No hyphae found on potassium hydroxide (KOH) scrapings.
- Postinflammatory hyperpigmentation – Sequelae of inflammatory skin condition; evidence of inflammatory condition prior to hyperpigmentation.
- Fixed drug eruption
- Acral nevi
- Postinflammatory hyperpigmentation
- Addison disease – Increased pigmentation resulting from increased levels of the pituitary hormones (melanocyte stimulating hormone [MSH] and adrenocorticotropic hormone [ACTH]) in Addison disease. Pigmentation usually occurs on the mucosa, elbows, knees, and dorsa rather than the plantar surface of hands.
- Vitamin B12 deficiency
- Laugier-Hunziker syndrome
- Secondary syphilis – Pink, red, violaceous, or brown macules or thin papules, smooth or scaly, may be tender on palpation. Other features of secondary syphilis may accompany palmoplantar manifestations.
Best Tests
Subscription Required
Management Pearls
Subscription Required
Therapy
Subscription Required
References
Subscription Required
Last Reviewed:03/20/2022
Last Updated:04/06/2022
Last Updated:04/06/2022