Pityriasis lichenoides et varioliformis acuta in Adult
A variant of PLEVA, febrile ulceronecrotic Mucha-Habermann disease (FUMHD), is marked by larger, more ulcerative, and necrotic lesions along with fever and arthralgia. There may be gastrointestinal, pulmonary, and central nervous system (CNS) involvement.
Pityriasis lichenoides chronica (PLC) is a related but more chronic form that is considered to be on a continuum with PLEVA. In contrast to the crusts, vesicles, and pustules seen in PLEVA, PLC takes on a more indolent course and is characterized by crops of scaly, erythematous papules that spontaneously regress over months to years. Overlapping cases of PLEVA and PLC do occur.
PLEVA is generally viewed as a benign lymphoproliferative disorder that lasts approximately 1-3 years. Duration has been associated with the distribution of lesions. Cases with diffuse skin involvement tend to have a shorter, approximately 11-month course, while acral-dominant cases have a longer course of approximately 33 months. Cases with a central distribution fall between these extremes.
The etiology of PLEVA is unknown but may be a lymphoproliferative response to a foreign antigen as it has been associated with viral infections, drugs, vaccinations, and radiocontrast dyes. There are case reports of progression to cutaneous T-cell lymphoma (CTCL). No guidelines have been established for monitoring this possible progression.
L41.0 – Pityriasis lichenoides et varioliformis acuta
86487001 – Acute lichenoid pityriasis
- Varicella – Prodrome of mild fever, malaise, and myalgia followed by pruritic, erythematous papules. Lesions are classically pruritic. Recurrent eruptions are not a feature of varicella.
- Arthropod bites and scabies
- Lymphomatoid papulosis – Predominantly CD30+ cells in the infiltrate, in older patients, characterized by more nodular lesions; active lesions do not spontaneously resolve as quickly as PLEVA.
- Vasculitis – Check serologies for rheumatoid factor (RF), antinuclear antibodies (ANA), anti-ds DNA, antineutrophil cytoplasmic antibody (ANCA), cryoglobulins, and C3 and C4 levels. Lesions are mostly purpuric and more monomorphous.
- Dermatitis herpetiformis – Exquisitely pruritic. Ruled out by direct immunofluorescence on the skin biopsy.
- Pityriasis rosea – Papulovesicular variety. Observe and/or seek history of herald patch.
- Lichen planus – Very pruritic; lesions are typically monomorphous and rarely crusted.
- Mycosis fungoides tends to present with larger patches and plaques.
- Perforating dermatoses
- Primary human immunodeficiency virus (HIV) infection
- Erythema multiforme
- Guttate psoriasis