PDA

View Full Version : Hy 2410 Skin Pathology (They’ll show you a picture…for sure)


tommyk
10-04-2006, 05:51 AM
Hy 2410 Skin Pathology (They’ll show you a picture…for sure)
A 30-year-old woman named Lucy Liu presents to a clinician because of an itchy a patch of skin near her knee. Around 6 months previously, she had had several mosquito bites in the relatively small area during a movie shoot. The mosquito bites eventually resolved, but the area had continued to be itchy, and she had continued to scratch it periodically. The well-defined 6-cm diameter patch of skin is now dry, scaling, hyperpigmented, and thickened. A ring of discrete brownish papules can be seen at the periphery of the lesion. Which of the following is the most likely diagnosis? (Yahoo! Or Google Image each of the following. A picture in Derm Path is completely key!)
1-Lichen simplex chronicus
2-Pompholyx
3-Psoriasis
4-Seborrheic dermatitis
5-Stasis dermatitis







































































a) This is lichen simplex chronicus, also known as localized scratch dermatitis and neurodermatitis. What basically happens is that the patient gets into a vicious cycle of itching causing scratching, which causes more itching. The initiating cause may or may not be known or remembered, but the process persists long after the inciting process has resolved. Stress and tension may exacerbate the process. The appearance described in the question stem is typical. Treatment involves breaking up the itch-scratch cycle, which may be difficult. Topical steroids may be helpful, as may covering the area with a dressing to make scratching more difficult. I have heard that frequent washing, taking oral Benadryl can also help. Listen, Pompholyx is a cause of marked erythema of the palms and soles. Psoriasis causes salmon-colored plaques with silvery scale. Seborrheic dermatitis (This is “dandruff”) causes dandruff and cradle cap. Stasis dermatitis is seen at the ankles and is related to varicose veins.

IMG SURVIVOR
10-05-2006, 12:21 PM
http://162.129.70.33/images/stasis_hyperpigmentation_1_041104.jpg





Stasis dermatitis is seen here. Years of poor circulation from poor cardiac function leads to chronic edema and venous stasis of blood with extravasation of red blood cells that leads to collection of hemosiderin to give the skin a brown appearance.

IMG SURVIVOR
10-05-2006, 12:35 PM
http://162.129.70.33/images/psoriasis_6_050308.jpg




This is psoriasis. The thick, silvery, scaling lesions are most often found over bony prominences, scalp, genitalia, and hands. It occurs when there is abnormal proliferation and turnover of epidermis (reduced from a month to only 4 days for a cell to transit from basal layer to surface).