Differential Diagnosis for Diffuse Rash with Circular Erythematous Lesions and Central Clearing with Pruritus
- Single most likely diagnosis
- Tinea corporis (ringworm): This is a common fungal infection that causes circular, erythematous lesions with central clearing and pruritus, making it the most likely diagnosis.
- Other Likely diagnoses
- Eczema (atopic dermatitis): Can present with diffuse rash and pruritus, although the lesions may not always have central clearing.
- Contact dermatitis: An allergic reaction to substances like plants, metals, or chemicals, which can cause a rash with similar characteristics.
- Pityriasis rosea: A skin condition that starts with a single patch (herald patch) followed by a diffuse rash with circular lesions and central clearing.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Lyme disease: Although less common, Lyme disease can cause a distinctive rash (erythema migrans) that is circular with central clearing, and missing this diagnosis can lead to serious complications.
- Rocky Mountain spotted fever: A tick-borne illness that can cause a rash, although it is typically more petechial and less likely to have central clearing.
- Rare diagnoses
- Erythema migrans-like lesions in southern tick-associated rash illness (STARI): A rare condition caused by the bite of the lone star tick, which can mimic the rash of Lyme disease.
- Granuloma annulare: A rare skin condition that can cause circular lesions with central clearing, although it is typically less pruritic and more localized.