Dermatology - Plaque Psoriasis

Dermatology - Plaque Psoriasis 
Psoriasis is usually a chronic condition. Environmental triggers include stress, bacterial infections, trauma, and certain medicines, in addition to polygenic predisposition. Any age can be the onset, with ages 8, 22, and 55 being the peaks. More severe disease is predicted by an early beginning. Lesions that persist for months or years affect the majority of patients.
Pruritus is prevalent, particularly in the anogenital and scalp areas.

Polycyclic, geographic lesions can grow from sharply marginated, dull-red plaques with loose lamellar, silvery-white scales. These could exhibit arciform, serpiginous, and annular patterns if they partially retreat. Unless the lesion is very persistent, lamellar scales can be easily eliminated. The sacralgluteal area, scalp, elbows, knees, palms, and soles are the preference sites for localizing lesions, which can be single or many. Lesions frequently spare exposed areas and exhibit bilateral symmetry. Massive hyperkeratosis that is glossy white or yellowish on the palms and soles, with a clearly defined base, is present. It is difficult to eradicate. Bleeding, painful fissures, and cracking are possible.

Plaques in the body folds are macerated, frequently bright red and fissured (inverse psoriasis), and lesions from intertrigo, candidiasis, or contact dermatitis can only be distinguished by a strong demarcation. Pitting, subungual hyperkeratosis, onycholysis, and yellowish brown patches beneath the nail plate—the so-called "oil spot" (pathognomonic)—are examples of nail alterations.

The differential includes seborrheic dermatitis, lichen simplex chronicus, drug eruptions, tinea, and mycosis fungoides. The diagnosis is clinical. Intertrigo, extramammary Paget disease, glucagonoma syndrome, Langerhans cell histiocytosis, and Hailey-Hailey disease are among the conditions on the differential for inverse psoriasis. Onychomycosis in the nails needs to be ruled out using KOH.
Topical fluorinated glucocorticoids with occlusion can be used to treat plaques; hydrocolloid dressing works well and keeps patients from scratching. It is beneficial to inject a 3 mg/mL triamcinolone acetonide aqueous suspension diluted with normal saline into lesions that are less than 4 cm.
Although less effective, tacrolimus 0.1% and vitamin D analogs are both good nonsteroidal medications.
The use of 1% topical pimecrolimus is beneficial for inverse psoriasis. Comparable in efficacy, tacarotene works best when used with topical class II glucocorticoids. All topicals can be used in conjunction with PUVA photochemotherapy and 311-nm UVB phototherapy. Oral retinoids or biologicals are recommended for severe, widespread illness. On the scalp, tar or ketoconazole shampooing works well, but firstly, 10% salicylic acid must be used to eliminate plaques. This is followed by betamethasone valerate. Topical therapies have no effect on nail lesions.