Pityriasis lichenoides et varioliformis acuta (PLEVA) is the acute form of an inflammatory skin condition called pityriasis lichenoides. People with PLEVA may develop a few to more than one hundred scaling papules which may become filled with blood and/or pus, or erode into crusted red-brown spots. Papules may itch or burn, and some people may experience fever or joint pain. Although PLEVA may occur at any age (including infancy), it most commonly affects children and young adults. A skin biopsy is needed to confirm the diagnosis. The exact underlying cause is unknown, but some scientists suspect that it may occur due to an exaggerated immune response to an infection or an overproduction of certain white blood cells (a lymphoproliferative disorder). If treatment is necessary, recommended therapies may include oral antibiotics, sun exposure, topical steroids, immunomodulators (medications used to help regulate or normalize the immune system), phototherapy and/or systemic steroids. PLEVA may last for a few weeks to years, and may fluctuate between getting better and worse before going away on its own.

Although PLEVA can affect almost any part of the body, it most commonly develops on the trunk, arms, and/or legs. The number of papules may range from a few to over one hundred. Individual papules often resolve after a few weeks, but new ones often develop as older ones resolve, resulting in ongoing symptoms. PLEVA may last for a few weeks to years, and may fluctuate between getting better and worse before going away on its own.

Aside from the skin features, most people do not experience additional signs and symptoms. However, some people experience fever, headaches, joint pain and/or swelling of nearby lymph nodes.

There is a rare subtype of PLEVA called febrile ulceronecrotic Mucha-Haberman disease (FUMHD) in which papules rapidly develop into painful, large, crusted ulcers and pus- or blood-filled blisters, which may become infected. People with FUMHD may also have symptoms such as high fever, sore throat, diarrhea, abdominal pain, neurologic abnormalities, lung disease, and other symptoms. In some cases, FUMHD can be fatal.

• Toxoplasma gondii
• Epstein-Barr virus
• HIV
• Cytomegalovirus
• Parvovirus (fifth disease)
• Staphylococcus aureus
• Group A beta-haemolytic streptococci

Others scientists think the condition may be a benign lymphoproliferative disorder. These conditions are characterized by an overproduction of certain white blood cells (lymphocytes) which can result in tissue and organ damage.

A diagnosis of pityriasis lichenoides et varioliformis acuta is often suspected based on characteristic signs and symptoms. A skin biopsy can be used to confirm the diagnosis. Additional laboratory testing may be ordered to investigate a possible cause such as an associated infection.

If treatment is indicated, there are many different therapies that have been used to treat PLEVA with varying degrees of success. These include:

• Oral antibiotics
• Sun exposure
• Topical steroids
• Immunomodulators (medications used to help regulate or normalize the immune system)
• Phototherapy
• Systemic steroids

Unfortunately, PLEVA may not always respond to treatment and relapses often occur when treatment is discontinued.

Febrile ulceronecrotic Mucha-Habermann disease (FUMHD), a rare, severe type of PLEVA, can be associated with serious complications and can be fatal, particularly in adults.