Psoriasis is a noncontagious skin disorder that most commonly appears as inflamed, edematous skin lesions covered with a silvery white scale. The most common type of psoriasis is plaque psoriasis
Causes • Lesions of psoriasis are caused by an increase in the turnover rate of dermal cells from the normal 23 days to 3-5 days in affected areas. • Patients with psoriasis have a genetic predisposition for the disease
Causes Autoimmune function: • Significant evidence is accumulating that psoriasis is an autoimmune disease. • Lesions of psoriasis are associated with increased activity of T cells in underlying skin. • Some of the newer drugs used to treat severe psoriasis directly modify the function of lymphocytes
History • Worsening of a long-term erythematous scaly area • Sudden onset of many small areas of scaly redness • Recent streptococcal throat infection, viral infection, immunization, use of antimalarial drug, or trauma • Family history of similar rash • pain • Pruritus • No fever • Vesicles • Long-term rash with recent presentation of joint pain
Physical • Plaque psoriasis is characterized by raised inflamed lesions covered with a silvery white scale. This is most common on the extensor surfaces of the knees, elbows, scalp, and trunk. • Guttate psoriasis presents as small red dots of psoriasis that usually appear on the trunk, arms, and legs; It frequently appears suddenly after an upper respiratory infection (URI).
Physical • Inverse psoriasis occurs on the flexural surfaces, armpit, groin, under the breast, and in the skin folds. • Pustular psoriasis presents as sterile pustules appearing on the hands and feet or, at times, diffusely.
Physical • Erythrodermic psoriasis presents as generalized erythema, pain, itching, and fine scaling. • Scalp psoriasis affects approximately 50% of patients, presenting as erythematous raised plaques with silvery white scales on the scalp
Physical • Nail psoriasis may cause pits on the nails, which may develop yellowish color and become thickened. Nails may separate from the nail bed. • Psoriatic arthritis affects approximately 10% of those with skin symptoms. The arthritis is usually in the hands, feet, and, at times, in larger joints. It produces stiffness, pain, and progressive joint damage
TREATMENT Many drugs that affect the rate of production of skin cells are used in psoriasis therapy alone or in combination with light therapy, stress reduction, and climatotherapy. Adjuncts to treatment include sunshine, moisturizers, and salicylic acid as a scale-removing agent. Generally, these therapies are used for patients with less than 20% of body surface area involved, unless the lesions are physically, socially, or economically disabling.
Treatment Keratolytic agents Coal tar Topical corticosteroids Vitamin D3 analogue
Treatment Treatments for more general or advanced psoriasis include UV-A light, psoralen plus UV-A light (PUVA), retinoid eg acitretin, methotrexate (particularly for arthritis), cyclosporine.
Treatment The recognition of the central role of T cells and tumour necrosis factor (TNF)-α in the pathogenesis of psoriasis led to the development of new biologic treatments.
Treatment Currently, three biologic TNF-α inhibitors: Infliximab Etanercept Adalimumab and two T-cell agents Efalizumab Alefacept
Treatment It is recommend that these biologic agents are used as a second-line therapy for patients with moderate-to-severe psoriasis who have: 1- failed to respond to conventional nonbiologic agents,
Treatment 2- Have become intolerant to conventional systemic therapy, and/or cannot receive conventional systemic therapy because of an increased risk of developing clinically relevant drug-related toxicity.
Treatment 3- cannot receive conventional systemic therapy because of an increased risk of developing clinically relevant drug-related toxicity.
Pityriasis rosea (PR) is a common benign papulosquamous disease. Pityriasis denotes fine scales, and rosea translates as rose colored or pink. PR can have a number of clinical variations. Its diagnosis is important because it may resemble secondary syphilis.
The disease typically begins with a solitary macule that heralds the eruption (called the herald spot/patch), which is usually a salmon-colored macule. This initial lesion enlarges over a few days to become a patch with a collarette of fine scale just inside the well-demarcated border.
Within the next 1-2 weeks, a generalized exanthem usually appears, although it may occur from hours to months after the herald patch. This secondary phase consists of bilateral and symmetric macules with a collarette scale oriented with their long axes along cleavage lines. This phase tends to resolve over the next 6 weeks, but variability is common.
Pruritus is common, usually of mild-to-moderate severity, and it occurs in 75% of patients.
Pathophysiology • PR has often been considered to be a viral exanthem. Its clinical presentation supports this concept. PR has been linked to upper respiratory infections,, the incidence may increase in the fall and the spring. A single outbreak tends to elicit lifelong immunity.
Despite these tendencies, no single virus has been proven to cause the disease
The most important part of treating patients with PR is reassurance that the rash will resolve. Generally, the disease resolves within 12 weeks
Relief of pruritus is helpful and can be accomplished by using topical steroids, oral antihistamines, topical menthol-phenol lotions, and oatmeal baths. Systemic steroids are not recommended
The prognosis for PR is excellent. Patients may return to work or school because they are not considered to be contagious.
Lichen planus (LP) is a pruritic, papular eruption characterized by its violaceous color; polygonal shape; and, sometimes, fine scale. It is most commonly found on the flexor surfaces of the upper extremities, on the genitalia, and on the mucous membranes