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New Treatments for Pityriasis Rosea

Pityriasis rosea is a benign, common eruption which occurs most frequently in children and young adults. Although a prodrome of fever, malaise, arthralgia, and pharyngitis may precede the eruption, children rarely complain of such symptoms. The cause of pityriasis rosea is unknown; a viral agent is for  pitiriasis is postulated.

Clinical Manifestations.

A herald patch, a solitary, round or oval lesion that may occur anywhere on the body and is often but not always identifiable by its large size, usually precedes the generalized eruption. Herald patches vary from 1-10 cm in diameter; they are annular in configuration.

When the disease is extensive, the face, scalp, and distal limbs may be involved, or, in the inverse form of pityriasis rosea, only those sites may be affected. Lesions may appear in crops for several days. Typical lesions are oval or round, less than 1 cm in diameter, slightly raised, and pink to brown. The developed lesion is covered by a fine scale that gives the skin a crinkly appearance; some lesions clear centrally, producing a collarette of scale that is attached.

The long axis of each lesion is usually aligned with the cutaneous cleavage lines, a feature that creates the so-called Christmas tree pattern on the back. Actually, conformation to skin lines is often more discernible in the anterior and posterior axillary folds and supraclavicular areas. Duration of the eruption varies from 2-12 wk. The lesions may be asymptomatic.

Diagnosis.

This is clinical. The herald patch may be mistaken for tinea corporis, a pitfall that can be avoided if testing with a potassium hydroxide preparation is carried out. The generalized eruption resembles a number of other diseases; of these, secondary syphilis is the most important. Drug eruptions, viral exanthems, guttate psoriasis, PLC, and eczema can also be confused.

Treatment.

Therapy is unnecessary for asymptomatic patients. If scaling is prominent, a bland emollient may suffice. Pruritus may be suppressed by a lubricating lotion containing menthol and camphor or by an oral antihistamine for sedation, particularly at night, when itching.

Occasionally, a nonfluorinated topical corticosteroid preparation may be necessary to alleviate pruritus. After the eruption has resolved, postinflammatory hypopigmentation or hyperpigmentation may be pronounced, particularly in black patients; these changes disappear during subsequent weeks to months.