Approach Considerations
Parapsoriasis can be managed conservatively on the basis of symptoms, and often, topical treatment is effective. A novel treatment of parapsoriasis reported in 2018 is hydrogen-water bathing. This modality proposes water with increased reactive oxygen scavenging properties as the mechanism. In a small study in which parapsoriasis patients were bathed twice weekly over 8 weeks, four of six showed partial responses and two had complete remission. The treatment was well tolerated. [16]
Small plaque parapsoriasis
Small plaque parapsoriasis usually is asymptomatic. Treatment should be based on alleviation of symptoms associated with scaliness, and patients should be reassured of the benign self-limiting nature of the disease.
Emollients may be sufficient to treat scaliness; however, a trial of midpotency topical steroids (class 3-5) may lead to greater clinical responsiveness.
Phototherapy is effective in treating lesions that are widely scattered. Broad- or narrow-band UV-B can be effective and can lead to remission. [17, 18] More recalcitrant presentations can be treated with psoralen and long-wave ultraviolet radiation (PUVA).
Annual follow-up is recommended. An increase in the number of lesions, an increase in the size of lesions, or the development of induration or epidermal atrophy should prompt a repeat skin biopsy to consider a diagnosis of mycosis fungoides (MF) in evolution.
Large plaque parapsoriasis
Large plaque parapsoriasis should be treated, because treatment may prevent progression to MF (cutaneous T-cell lymphoma [CTCL]). Therapy includes mid- to high-potency topical steroids (class 2-4), topical nitrogen mustard, and topical carmustine (BCNU). Patients using topical treatment need follow-up every 2-3 months. [19]
Phototherapy with either broad- or narrow-band UV-B or PUVA can be effective in inducing remission. Phototherapy requires an evaluation to response after every 8-12 visits or monthly.
Large plaque parapsoriasis requires closer follow-up than small plaque parapsoriasis. Follow-up frequency is determined by the treatment modality used. Follow-up every 6 months is recommended. Increasing number of lesions, increase in lesion size, or the development of induration or epidermal atrophy should prompt a repeat skin biopsy to consider a diagnosis of MF in evolution. If patients remit or do not desire treatment, follow-up is still recommended to assess for recurrence or progression.
Complications
Administration of topical chemotherapy agents may result in development of contact dermatitis.
Consultations
Consult with a dermatologist specializing in cutaneous lymphoma to coordinate medical care if progression to MF (CTCL) occurs.
-
Small plaque parapsoriasis.
-
Small plaque parapsoriasis.
-
Large plaque parapsoriasis.
