Causes and risk factors
The exact cause is unknown. It is known to be a cutaneous lymphoproliferative disorder. It is classified into small plaque parapsoriasis [SPP] and large plaque parapsoriasis [LPP]. SPP is a benign and chronic condition. LPP is at a greater risk to develop into cutaneous T-cell lymphoma.
Clinical presentation
The lesions of parapsoriasis develop slowly. Lesions of SPP are spread over extremities and trunk. They are usually less than 5 cm in diameter. They are well circumscribed. The lesions are scaly. LPP lesions have geographic borders. They are more than 5 cm in diameter. They are erythematous, slightly red in color. They spread over extremities and trunk. The lesions show thin, scales with skin of tissue paper consistency.
Investigations
Medical history by the patient and clinical examination by the doctor helps in diagnosis. Skin biopsy is done. Routine blood tests are recommended.
Treatment
A small plaque type is usually benign and treatment, though not necessary, can include emollients, topical tar preparations, or corticosteroids, and/or phototherapy. A large plaque type is treated with phototherapy or topical corticosteroids.
Complications
LPP is a precursor of cutaneous T-cell lymphoma [CTCL]. LPP may progress to mycosis fungoides.
When to Contact a Doctor
One must consult a doctor if there are abnormal patches on the skin.
Systems involved
Integumentary system, immune system
Organs involved
Skin
