- Clinical science
The term “parapsoriasis” covers a large group of idiopathic cutaneous diseases characterized by asymptomatic or mildly pruritic, erythematous, scaly patches, and a chronic course. The condition is roughly classified into two types: large plaque parapsoriasis and small plaque parapsoriasis. Large plaque parapsoriasis is considered a premalignant condition that can progress to mycosis fungoides. Diagnosis is based on clinical examination and histopathological findings on biopsy. Treatment includes topical steroid therapy and phototherapy.
- Rare disorder
- Sex: ♂ > ♀
Epidemiological data refers to the US, unless otherwise specified.
- Group of cutaneous diseases of unknown etiology
- Skin lesions (i.e., papules, patches, or plaques) caused by T-cell infiltration into the skin
The term “parapsoriasis” has its roots in its dermatological similarity to psoriatic lesions (e.g., plaques and scaly patches) seen during efflorescence.
- Round or oval, scaly, salmon-colored or yellow-brown patches
- Benign; chronic course (months to years); resolves spontaneously
- Diagnostics: Skin biopsy
- Clinical features
- Diagnostics: : skin biopsy
- Treatment: always indicated, because treatment may prevent progression to mycosis fungoides or cutaneous T-cell lymphoma.
|Differential diagnosis of Parapsoriasis|
|Small plaque psoriasis|| |
|Large plaque psoriasis|
The differential diagnoses listed here are not exhaustive.