Classic Pityriasis Rosea

In 80% of cases, a bright, oval, slightly raised "herald" patch 2 to 5 cm in diameter appears at the onset of the disease, usually on the trunk. The center of the herald patch shows scaling. One to two weeks later, multiple edematous, pinkish erythematous-squamous patches appear, 2-3 cm in diameter, typically round or oval in shape, arranged along the lines of Langer (on the back, resembling a "Christmas tree" pattern). The central portion of these patches is delicately folded, sometimes pigmented, and associated with scaling. The scaling is more pronounced at the border between the central and peripheral zones.

In 20% of cases, the "herald" patch is absent, or multiple "herald" patches may be present. In rare cases, the "herald" patch is the only skin lesion ("unheaded" pityriasis rosea).

The lesions do not appear simultaneously, resulting in an evolving polymorphism. The lesions begin to dissolve from the central part, which is pigmented, loses its bright color and begins to desquamate. The ring of erythema gradually disappears, leaving a mild hyperpigmentation.

Pityriasis rosea does not usually recur. Spontaneous healing occurs around the 4th to 5th week of the disease. Residual clinical manifestations are uncommon. In some cases, hypo- or hyperpigmentation may occur, often exacerbated by sun exposure or ultraviolet therapy.

Irritated Pityriasis Rosea

Characterized by itching, swelling and erythema of the skin lesions. It is often caused by excessive irritation from the use of antiseptics, alcohol-based solutions, antifungal agents, or mechanical friction (scrubbing, tight clothing).

Pityriasis Circinata et Marginata of Vidal

This is considered a chronic form of pityriasis rosea. It is characterized by few eruptions that are sharply demarcated from healthy skin. The lesions are oval or round in shape, pink or reddish-yellow in color, with slight scaling that is more pronounced at the periphery, giving the rash a ring-like appearance. Typical pityriasis rosea eruptions may coexist. Subjective symptoms are usually absent. The dermatosis is chronic and eruptions may persist for months or even years.

Pityriasis Rosea-like Drug Eruptions

Some medications may cause a rash that clinically resembles pityriasis rosea but lacks the characteristic "herald patch" and has papular lesions. The eruptions progress with continued use of the drug, but resolve spontaneously after discontinuation of the drug. Reported cases have been associated with:

• ACE inhibitors
• Isotretinoin
• Non-steroidal anti-inflammatory drugs (NSAIDs)
• Omeprazole
• Terbinafine
• Tyrosine kinase inhibitors

Atypical Forms of Pityriasis Rosea

Urticarial

Follicular

Vesicular

Acral

Papular

Inverse

Oral mucosa

Giant

Hypopigmented

Segmental

Erythema multiforme-like

Pityriasis amiantacea-like

The diagnosis is based on the patient's history (association with a recent infection, exposure to cold, general health disturbance) and the clinical presentation of the disease (presence of the "Herald patch", erythematous-squamous elements arranged along Langer's lines).

Diagnostic criteria (Chuh A.A. 2003):

Main criteria:

• Isolated eruptions with a ring-shaped or round form.
• Scaly surface of the lesions.
• Peripheral scaling in the form of a "collarette."

Additional criteria:

• Localization on the trunk and proximal areas.
• Arrangement along Langer's lines of skin tension.
• Presence of "herald patch" preceding the eruptions.

Laboratory tests:

• Routine compete blood count and urinalysis tests.
• Serological tests to rule out syphilis.
• Microscopic examination of skin scrapings to rule out fungal infections.

• Nummular Eczema
• Psoriasis
• Pityriasis Lichenoides
• Small Plaque Parapsoriasis
• Large plaque parapsoriasis
• Syphilitic Roseola
• Papular Syphilis
• Tinea Corporis

Spontaneous healing usually occurs within 4-5 weeks of the onset of the disease. Uncomplicated cases of pityriasis rosea do not require treatment.

Treatment is indicated for generalized skin involvement, significant exudative eruptions, allergic reactions, or pruritus.

For widespread skin involvement accompanied by severe itching:

Topical glucocorticosteroids:

• Hydrocortisone butyrate cream or ointment 0.1%, applied 1-2 times daily for 5-7 days.
• Alclometasone dipropionate cream or ointment 0.05%, applied 1-2 times daily for 5-7 days.
• Methylprednisolone aceponate cream or ointment 0.1%, applied 1-2 times daily for 5-7 days.
• Mometasone furoate cream or ointment 0.1%, applied 1-2 times daily for 5-7 days.

Antihistamines:

• Cetirizine hydrochloride: Adults and children over 6 years old, a daily dose of 10 mg orally for adults (1 dose) and 5 mg orally twice a day for children for 7-10 days.
• Loratadine: Adults and children over 12 years old, 10 mg orally once a day; for children aged 3 to 12 years with a body weight less than 30 kg, 5 mg orally once a day, and for children with a body weight over 30 kg, 10 mg orally once a day for 7-10 days.
• Chloropyramine: For children aged 1 to 6 years, 8.3 mg orally 2-3 times a day; for children aged 6 to 14 years, 12.5 mg orally 2-3 times a day; for adults, 25 mg orally 3-4 times a day for 7-10 days.
• Clemastine: For children over 7 years old, 0.5-1 mg orally twice a day; for adults, 1 mg orally twice a day for 7-10 days.

In complicated forms of the disease, systemic glucocorticosteroid may be prescribed:

• Prednisone 15-20 mg daily orally until symptoms are alleviated.