Psoriasis Area and Severity

The psoriasis area and severity index is a uniform method to determine the extent of body surface area affected, along with the degree of erythema, induration, and scaling. Severity scores are rated as <12 (mild), 12 to 18 (moderate), and >18 (severe). 

Efficacy Psoriasis Area and Severity Index (PASI)—extent of area affected and severity of erythema, scaling, and thickness of plaques... 

Psoriasis Phase II study 12 weeks Leflunomide 20 mg/day n = 8) 6/8 clinical effectiveness (psoriasis area and severity index score 20 at baseline versus 13 at 12 weeks) (27)... 

A coal tar solution (crude coal tar diluted to 20% with ethanol and polysorbate 80) was applied to clinically unaffected skin of three patients with severe atopic dermatitis and six patients with generalized psoriasis (Bickers and Kappas 1978). Another skin area at least 10 cm away was not treated or was treated with 100 mL of the vehicle alone. Twenty-four hours later, a 6-mm punch biopsy was obtained from coal tar treated and control areas and the effect on AHH activity was determined. Application of coal tar to the skin caused induction of cutaneous AHH activity that varied from 2.4- to 5. 4-fold over the enzyme activity in untreated skin areas, suggesting absorption after topical application. 

This work finally resulted in a new protocol for treating psoriasis, a chronic skin disease that can be seriously debilitating. The patient receives successive oral doses of methoxsalen followed by ultraviolet irradiation of the affected areas of skin. The procedure effectively controls psoriasis, and with improvements incorporated over the past twenty years it has become a standard therapy. Related procedures bring relief from several other skin diseases. In addition, the combination of psoralens and light has a key role in a promising treatment now under development for a white blood cell cancer. 

In 1937, Silver reported the clinieal use of hematoporphyrin and UV-light in the treatment of psoriasis [70,71]. After systemically injected hematoporphyrin derivative (HPD) in combination with red laser light (630 nm, 40 and 20 J cm 2), psoriasis lesions in the mons pubis area responded vigorously in a patient treated for intraepithelial neoplasia of the vulva [72]. An improvement greater than 90% was achieved in 15 out of 19 patients after a low dose of HPD (1.0 mg kg ) and daily whole body irradiation with UVA light for 15 days [73]. The optimum irradiation time for psoriatic lesions is 6 h after topically applied ALA [74]. Several other authors treated psoriasis at different locations on the body and suggest that PDT with topical, applied photosensitizers is a well tolerated additional treatment [751. 

A 51-year-old man presented with plaque-type psoriasis took etanercept and 2 years later developed painful ulcers in the mouth and on the penis, shoulders, chest, and back. Etanercept was withdrawn and most ot the lesions cleared within a tew weeks. Several months later, etanercept was started again, but within 3 months he developed more lesions on the chest and back, in the mouth, and in new areas in the inguinal region and on the limbs. A biopsy showed suprabasal acantholysis and intercellular deposition of IgG and C3. 

Autacoids Recurrent angioedema has been reported in a 63-year-old man with severe plaque psoriasis after efalizumab treatment for 15 weeks [233 ]. There was swelling of the periorbital area, cheek, tongue, and Ups, and after the next dose he developed the same sjmiptoms as weU as acute abdominal pain. Efalizumab was withdrawn and the sweUing and abdominal pain resolved within 3 weeks. 

Psoriasiform erythroderma is really a congenital psoriasis, but the gross and histologic features resemble a severe ichthyosiform erythroderma, marked by conspicuous loss of large, micaceous scales for several months. Some normal skin areas are often distinctive. Only the appearance of typical psoriatic patches or pustular psoriasis during childhood permits this diagnosis to be confirmed, as we have also personally observed in our patients. 

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