A skin disorder typi?ed by a bran-like desquamation (?aking). There are several varieties including P. alba, rosea, versicolor (fungal caused) and rubra (exfoliative dermatitis).
Pityriasis alba is a mild form of chronic eczema (see DERMATITIS) occurring mainly in children on the face and in young adults on the upper arms. It is characterised by round or oval ?aky patches which are paler than the surrounding skin due to partial loss of MELANIN pigment. The appearance is more dramatic in dark-skinned or suntanned subjects. Moisturising cream often su?ces, but 1 per cent HYDROCORTISONE cream is more e?ective.
Pityriasis rosea is a common self-limiting eruption seen mainly in young adults. It usually begins as a solitary red ?aky patch (often misdiagnosed as ringworm). Within a week this ‘herald patch’ is followed by a profuse symmetrical eruption of smaller rose-pink, ?aky, oval lesions on the trunk and neck but largely sparing the limbs and face. Itching is variable. The eruption usually peaks within 3 weeks and fades away leaving collarettes of scale, disappearing within 6–7 weeks. It rarely recurs and a viral cause is suspected but not proved. It is not contagious and there is no speci?c treatment, but crotamiton cream (Eurax) may relieve discomfort.... pityriasis
A common, mild skin disorder in which a rash of flat, scaly-edged, pink spots or patches appears on the trunk and upper arms. It is not contagious and mainly affects children and young adults. Its cause is unknown. The rash lasts for 4–8 weeks, may cause itching, and usually clears up without treatment. Calamine lotion or antihistamine drugs may relieve any itching. pityriasis versicolor A common skin condition in which patches of white, brown, or salmon-coloured flaking skin appear on the trunk and neck. Also known as tinea versicolor, it is caused by a fungus that exists on most people’s skin. Treatment is with antifungal drugs. pivampicillin See penicillin drugs. pivmecillinam See penicillin drugs. pizotifen An antihistamine drug used to prevent migraine in people with frequent, disabling attacks. Adverse effects can include nausea, dizziness, drowsiness, dry mouth, and muscle pains.
Prolonged use may cause weight gain.... pityriasis rosea
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