A mild inflammatory skin disease of unknown etiology, characterized by scaly damage, with a self-limiting course (6-8 weeks). Performance for the trunk mainly, the neck, and the proximal extremities a little rose furfur rash, rash is rose-red, slightly higher than the skin, some contained in the skin, size varies, some like small button size, some like coin size, oval, covered with a layer of bran-like thin skin, called bran-like scales. Can occur in any age, but mostly seen in young people. Infection factors that have been isolated are mycoplasma, micro RNA virus and human herpes virus. Its incidence is highest in the warm season and in spring and autumn. Parapsoriasis is not self-healing and is not associated with colds, and the rash is widely distributed. To differentiate, a piece of skin can be taken for histopathological examination, which can clarify the diagnosis. Signs and symptoms Usually 5-7 days before the generalized rash, a precursor spot (mother spot) is most often found on the trunk, typically 2-7 cm in diameter, which may be mildly erythematous, rose or light yellow-brown, circular or ovoid, scaly, with slightly raised margins, and sometimes confused with superficial fungal infections (e.g. ringworm). After the pioneer spots there are many similar small spots 0.5-2 cm in diameter that may continue to appear for several weeks, usually in a centripetal distribution on the trunk. On the back, the long axis is parallel to the dermatoglyphic line, with a typical radial arrangement seen from the spine. In blacks, the lesions are initially papular and less scaly. The distribution is atypical, with the lesions mainly affecting the arms and occasionally the face. There are usually no systemic symptoms, but occasionally mild fatigue and headache, and sometimes annoying itching may be present. It usually resolves spontaneously over 4 or 5 weeks, but the entire lesion may last for 2 months or longer. Recurrence is rare. Diagnosis and treatment Pityriasis rosea must be distinguished from ringworm, lichen planus, drug rash, psoriasis, paronychia, chronic mossy pityriasis, lichen planus, and second-stage syphilis, the most important of which is second-stage syphilis. When the palmoplantar is involved or does not see the pioneer spot or the clinical manifestation is not typical, must carry on the syphilis serological examination. If a patient with pityriasis rosea does not fade within 10 weeks, the possibility of plaque psoriasis should be considered. There are two types of parapsoriasis: the small plaque type, which is benign, and the large plaque type, which is usually a precursor to cutaneous T-cell lymphoma. Treatment is usually non-specific and is not usually required. Patients need to be reassured that the damage will subside on its own. Artificial or natural sunlight exposure may induce regression. Weak to moderately potent corticosteroid creams may reduce erythema and pruritus. Inflammation and pruritus can also be treated with 0.25% menthol added to snow cream. Topical preparations are also available with the local anesthetic pramoxine, which may or may not contain corticosteroids, and oral antihistamines. Prednisone is used only in the most severe cases (10 mg orally four times a day until the itching subsides, then the dose is reduced for about 14 days or more).