Pityriasis lichenoides is a relatively rare skin disorder that appears mainly in adolescents and young adult males. The onset may resemble an acute infection, with symptoms such as fever, malaise, and fatigue, and a few days later reddish-brown skin lesions appear. These lesions may be macules, papules, or more rarely vesicles, and are mainly located on the trunk, arms, and thighs. In some cases, the mucous membranes of the mouth or genital organs may also be affected. The inflammation is mild, without intense itching, and the disease usually resolves spontaneously within a few weeks to months, without leaving scars.
Diagnostic accuracy
Personalized treatment, tailored to the needs of each patient
Immediate results
Prevention of recurrences
Etiology
The exact causes of pityriasis lichenoides remain unknown, but several theories exist regarding its origin. It has been suggested that it is a reaction of the immune system to external stimuli such as:
viral infections: e.g. chickenpox, Epstein–Barr virus, HIV, parvovirus B19
Pityriasis lichenoides is divided into two main forms, which differ in clinical presentation, progression, and chronicity:
Acute pityriasis lichenoides (PLEVA – Pityriasis Lichenoides et Varioliformis Acuta):
This is the most inflammatory form, with a rapid onset and intense symptoms.
It is seen mainly in adolescents and young adults and is characterized by the appearance of small red papules, crusts, or vesicles that develop into scabs or necrotic lesions.
The lesions may resemble chickenpox-like rashes, hence the term “varicelliform.”
They usually appear on the trunk and limbs and may leave small scars or post-inflammatory hyperpigmentation.
The flare-up duration ranges from a few weeks to up to two months.
The lesions are usually reddish-brown flat papules, a few millimeters in diameter, with a fine adherent scale on their surface.
They mainly affect the extremities and trunk and often follow a relapsing course.
Although they do not cause significant discomfort, they may persist for months or even years.
In some cases, features of both forms may appear alternately or even simultaneously.
Diagnosis
Diagnosis is made through medical history and dermatological examination. However, a skin biopsy is required for confirmation, as pityriasis lichenoides can resemble guttate psoriasis. Both conditions occur more frequently in young people and are associated with infections, making differential diagnosis without biopsy difficult.
Prognosis and treatment
Pityriasis lichenoides often has an unpredictable course. The acute form may resolve within a few weeks, while in other cases it progresses to chronic, with flare-ups and remissions lasting months or years. Treatment is mainly based on empirical data and is personalized depending on disease severity. First-line options include:
Antibiotics such as azithromycin or erythromycin, mainly for their anti-inflammatory properties.
Topical corticosteroids or calcineurin inhibitors, for mild lesions.
UVB phototherapy, considered the most effective treatment for extensive disease.
In resistant cases, the following may be needed: methotrexate, dapsone or retinoids, more rarely PUVA, cyclosporine, or biological agents (such as TNF or JAK inhibitors), especially when there are severe systemic manifestations.
Diagnosis and therapeutic management often require long-term monitoring.
At Optimum Dermatology, a personalized approach is chosen, aiming at the most appropriate treatment for each case, while the course of the disease usually lasts from 6 to 12 months.
