A 13-year-old girl with reddish psoriatic plaques on lower limbs 银屑病
A 13-year-old girl was seen in the clinical centre because of reddish plaques with loosely adherent silvery-white lamellar scales on her two legs (Fig.1-A). The patient had been well until approximately 6 years earlier, when she fell down and injured her knees, a sharply marginated erythematous papule with a silvery-white scale developed on her knees, the scales are lamellar, loose and easily removed by scratching. During the next 5 years, the patients applied various creams and ointments, the lesion subsided then later on flared up and spread when the topical cream discontinued. Patient has no familial history of skin diseases.
On the examination, the patient’s temperature, pulse, respiratory rate and blood pressure are in normal range, removal of skin lesion scale resulted in the appearance of minute blood droplets. She was administered Tangs Psoria Capsule 1440mg three times daily, and Johnson-Johanson baby lotion to moisturize the dry lesion; no immunosuppressant therapy was given, her psoriasis lesion flared up in month 2 (Fig.1-B), which was caused by steroid withdraw effect, and thereafter responded very well (Fig.1-C,D).
Diagnosis
The classic lesion of psoriasis is a well-demarcated, raised, red plaque with a white scaly surface. Lesions can vary in size from pinpoint papules to plaques that cover large areas of the body. Under the scale, the skin has a glossy homogeneous erythema, and bleeding points appear when the scale is removed, traumatizing the dilated capillaries below (the Auspitz sign). Psoriasis tends to be a symmetric eruption, and symmetry is a helpful feature in establishing a diagnosis. Unilateral involvement can occur, however. The psoriatic phenotype may present a changing spectrum of disease expression even within the same patient. The Koebner phenomenon (also known as the isomorphic response) is the traumatic induction of psoriasis on non-lesional skin; it occurs more frequently during flareups of the disease, and is an all-or-none phenomenon (ie., if psoriasis occurs at one site of injury it will occur at all sites of injury). The Koebner reaction usually occurs 7 to 14 days after injury, and approximately 25 percent of patients may have a history of traumarelated Koebner phenomenon at some point in their lives. Estimates of lifetime prevalence rise to as high as 76 percent when factors such as infection, emotional stress, and drug reactions are included.1 The Koebner phenomenon is not specific for psoriasis but can be helpful in making the diagnosis when present.
