Differential Diagnosis for a Rash Mistaken for Ringworm
- Single most likely diagnosis:
- Nummular dermatitis: This condition is characterized by coin-shaped patches of eczema that can resemble ringworm. It's a common skin condition that can be mistaken for ringworm due to its similar appearance.
- Other Likely diagnoses:
- Psoriasis: Plaque psoriasis can sometimes present with ring-shaped lesions, especially when the scales are removed, making it a possible mimic for ringworm.
- Seborrheic dermatitis: This condition can cause a red, itchy rash on the skin, which in some cases may resemble ringworm, particularly when it affects the face or torso.
- Eczema (atopic dermatitis): Eczema can cause a variety of skin lesions, including some that might be mistaken for ringworm, especially in children.
- Granuloma annulare: This is a benign skin condition characterized by a ring-shaped lesion, which can be mistaken for ringworm.
- Do Not Miss diagnoses:
- Lyme disease: The rash associated with Lyme disease (erythema migrans) can sometimes be mistaken for ringworm. It's crucial to consider this diagnosis due to the potential for serious complications if left untreated.
- Syphilis (secondary): The rash of secondary syphilis can be varied and might include ring-shaped lesions, making it a critical diagnosis not to miss due to its implications for public health and the individual's health.
- Rare diagnoses:
- Erythema annulare centrifugum: A rare condition characterized by a ring-shaped eruption that migrates outward, which could be mistaken for ringworm.
- Subacute cutaneous lupus erythematosus: This autoimmune condition can cause skin lesions, including some that might resemble ringworm, although it is less common.
- Sarcoidosis: In rare cases, sarcoidosis can cause skin lesions that might be mistaken for ringworm, particularly the annular (ring-shaped) form.