Differential Diagnosis for Diffuse Psoriatic Plaques without Arthritis
- Single most likely diagnosis
- Psoriasis: This is the most likely diagnosis given the presence of diffuse psoriatic plaques, which are characteristic of the condition. Psoriasis is a chronic autoimmune skin disorder that can present with various types of lesions, including plaques.
- Other Likely diagnoses
- Seborrheic dermatitis: This condition can present with diffuse erythematous plaques, particularly on the scalp, face, and torso, which might be confused with psoriatic plaques.
- Pityriasis rubra pilaris: A rare skin disorder characterized by reddish-orange plaques and palmoplantar keratoderma, which could be considered in the differential diagnosis of diffuse psoriatic plaques.
- Nummular dermatitis: Also known as discoid eczema, this condition presents with coin-shaped patches of eczema that can resemble psoriatic plaques.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Cutaneous T-cell lymphoma (Mycosis fungoides): Although rare, this condition can mimic various dermatoses, including psoriasis, and is critical to diagnose early due to its potential for severe outcomes.
- Syphilis (secondary): This infectious disease can cause a wide range of skin manifestations, including diffuse plaques, and is crucial to identify due to its systemic implications and the importance of early treatment.
- Rare diagnoses
- Parapsoriasis: A group of rare skin disorders that can present with diffuse, scaly plaques, which might be considered in the differential diagnosis of psoriasis, especially if the presentation is atypical.
- Lichen planus: While typically presenting with purplish, itchy, flat bumps, lichen planus can occasionally manifest with more diffuse lesions that might resemble psoriatic plaques.