The itching is alleviated with drying and anti-pruritic lotions, like calamine loticn with half percant menthol OF phenol.

Infiammation, lesions may contain small vesicles. Pruritus varies from case to case. The lesions disappear in 6-8 weeks.
Management; 1. The itching is alleviated with drying and anti-pruritic lotions, like calamine loticn with half percant menthol of phenol. 2 Antistaminics may ba raquired orally for pruritus 2. Psoriasis Definition; A chronic, recurrent, inflammatory diseaseof the skin of unknown origin, characterized by well-circumscribed erythematous, dry plaques of various sizes, covered with mica-Iike scales. Etiology -(a)Gencetics; (i) Many pts have a fust degree relative with psoriasis, (ii) Siblings, of psoriatic pts have an 8% risk of developing the disease, 16% risk if one parent has psoriasis and 50% if both parents have the disease (b) Environmentl factors - Attacks of psoriasis can be precipitated or aggravated by stress. infection (streplococcal. HIV), pregnancy, trauma. drugs (chloroquine/antimalarials, lithium), alcohol, tobacco smoking, sunlight. Clinical features; Erupiton - (a) Onset and character - The initial lesion e a papula covered with silvery scales. The papuls gradually enlarges penpherally and scales increase to a mass. The removal of the scales exposes pinpoint bieeding points (Auspllz sign). (b) Sites-The lesions occur predominately on the extensors of the extremtias especially the elbows, knees. sacrum and occput, but may occur anywhere on tha body. The lesions are prona to occur at sites of trauma (Koebner phenomenon). MORPHOLOGICAL VARIETIES 1. Chronic stable plaque psoriasis (Psoriasis vulgaris, nummular psoriasis) - is the most common form, Lesions are well defined, with sharply delineated edge, erythematous (salmon pink), coverad with silvery white scales. Discs of varying size on trunk. limbs and scalp. There may be single lesion or multiple lesions. The psoriatic plaque is encircled by a clear peripheral halo.2. Guttate psoriasis - Shower of small, round to oval, monomorphic lesions generally over the body particularly in children and young aduits and usually after acute streptococcal Infection. 3. Rupoid. elephantine psoriasis - Limpet like lesions with cone shaped hyperkeraiosis seen particularly on the feet. Elephanilne psoriasis dascribes the rare but very persistant, thick scaly and large plaques on back, limbs. hips and elsewhere Erythrodemic psoriasis - Types; (a) Chronic psoriasis may evolve gradually into exfoliative phase or occur as initial manifeslation. Almost all cutaneous surfaces are involved. Prognoses good (b) Part of spectrum of unatable psoriasis it can be precipicated by infection. antimalarials, tar. dithranol, corticosteroids and hypocalcemia. There is generalised erythema and profuse scaling. Pt is febrila and relapses are frequent. Pruritus is often severe. Sarlous metabrdlic complications can occur. 5 Pustular psoriasis - Localised (hands and feet) or ganaralised. Tha term is reserved for those forme in which macroscopic pustules appear. 6. Psoriatic arthritis - Association of psoriasis with a peripheral and/or spinal arthropathy involvement of distal interphalangeal joint is typical 7. Penis - The scaly patch on glans penis may lack scales but other characteristics are retained 8. Muosal involvement - is rare and seen more often in pustular and exfollative forms of the disease. Grey, yellow or white, well-demarcated plaques or annular lesions affect buccal mucosa, palate and tongue. Pattern of geographical tongue may also develop. REGIONAL VARIETIES - Certain varieties of psoriasis affect some parts of the body only. 1. Flaxural psoriasis - the interitnginous areas are affected like the axillae, groins, under the breasts, cubtial and popliteal regions. 2. Palmar and plantar psoriasis -involving the palms and soles with hyperkeratotic, scaly patches. 3. Scalp psoriasis -Discrete areas of scaling often thicker than elsewhere. Beneath this scaling, the- scalp has the typical psoriatic red hue. 4 Psoriasis of the nails - is associated with pitting and transverse ridging of the nail plate. There subungual hyperkeratoaes as well as red onycholyais Management Although there are many therapies for the control of psorasis, there is no way to predict or prevent recurrences. GENERAL -(a) Remove trigger factor if possible (b) A warm climate may help to control relapses TOPICAL TREATMENT 3. Lichen Planus Definition: It is an inflammatory disorder of the skin and mucous membranes, of unknown origin, characterzed by violaceous, scaling, angular papules on Ihe flexor surfaces of the skin, and in the mouth, usually resolving in 1 to 2 years; considered to be a cell-mediated autoimmune disorder. Clinical features: Typical striae lesions - Violaceous, flat topped, polyhedral papules wrth a firmly attached scale. Faint streaks on the surface of the lesions can ba seen with a lens (Wickfhams striage) Lesions are produced at sites of traurma (Koebner phenomenon) In the mouth. it appears as spots, streaks, or a lacy network. Sites - usually bilateral and symmetrical: front of the wrists, flexor surface of forearms. shins, lower back and genitalia ara the comnon sites Itching severe at times. Mucous membrane lesions -are present in 65% of patients. These are white reticulate areas seen most commonly on buccal mucosa. palate, or vulva VARIETIES 1 Annular lichen planus -Ringed lesions. 2. Hypertrophic: lichen planus - Thick plaques usually in lower extremities 3. Linear form - along nerve segments 4 Lichen planopilaris - Follicular