What is Parapsoriasis?
“Parapsoriasis” is a skin condition that usually occurs in adults and is characterized by red or grayish scaly patches of varying sizes. These patches can resemble other skin conditions such as psoriasis or eczema.
The diagnosis of parapsoriasis is typically made through a biopsy. However, multiple biopsies taken at different intervals may be required to confirm the diagnosis.
Parapsoriasis is often resistant to treatment and can persist unchanged for long periods of time. It is rare in the general population.
There are two types of parapsoriasis: small plaque parapsoriasis and large plaque parapsoriasis. In both types, the rashes typically do not cause significant symptoms, though there may be mild itching at times. While small plaque parapsoriasis is considered a benign condition, large plaque parapsoriasis can transform into a cancer known as mycosis fungoides.
Types of Parapsoriasis
Small Plaque Parapsoriasis: In small plaque parapsoriasis, the patches are usually 2 to 5 cm in diameter and can be pink, grayish, or yellow-brown in color. The rashes are often round or oval in shape and commonly appear on the trunk, sides of the waist, and upper parts of the arms and legs.
Large Plaque Parapsoriasis: The rashes in large plaque parapsoriasis are larger than 5 cm in diameter. They may have irregular shapes and darker red, brown, or grayish colors. Additionally, there might be features such as speckled spots (poikiloderma), small blood vessels (telangiectasia), and skin thinning (epidermal atrophy).
Treatment of Parapsoriasis
For small plaque parapsoriasis, treatment may not be necessary if the patient is asymptomatic. However, if there is itching or cosmetic and psychological concerns, corticosteroid creams and moisturizers can be used.
Corticosteroid creams are usually applied twice daily for 2-3 months with breaks. If there’s no improvement in the patches, the treatment is discontinued. Even if the rashes completely disappear, recurrence after several months is common.
If creams are ineffective, phototherapy (light therapy) can be considered. In some cases, the patches may resolve on their own over time without any treatment.
As for large plaque parapsoriasis, since it can transform into mycosis fungoides (a type of cancer), treatment and monitoring are important. Treatment options include corticosteroid creams, moisturizers, or light therapy. Additionally, biopsies should be performed every 6 months to 1 year, or if there are changes in the rash, to check for the presence of mycosis fungoides transformation