Psoriasis

Pigmentation means discolouration of the skin. There may be increased pigmentation (Melasma, solar melanosis, freckles, Drug induced pigmentation etc.) or decreased pigmentation (healing lesions, pityriasis alba, leprosy etc.) or complete absence of pigment (Vitiligo) 

Psoriasis is an exfoliating disorder of skin where the skin cells multiply and grow rapidly and get shed.it is not a contagious disease. 

Cause:

 It is an immune-mediated disorder with genetic predisposition in which the excessive reproduction of skin cells is secondary to factors produced by the immune system.

Areas affected:

Thick plaques frequently occur on the skin of knees, elbows,and lower back. But it can involve any area like scalp, palms, soles and nails.it is a chronic recurring condition with exacerbation during winter season.In 10% of cases it affects joints known as psoriatic arthritis.it can be triggered by an injury to skin known as koebner phenomenon. 

Complications:

Topical application of native medicine, infections or sudden stopping of treatment may result in sevre variety of psoriasis like erythroderma or pustular psoriasis.

Treatment:

 Bath solutions and moisturisers soothen the skin and reduce dryness.If area of involvement is < 20%, then creams and ointments should suffice. If >20% of the body surface area is involved then oral drugs are required. 

Other treatment options:

1) Phototherapy: NBUVB, EXCIMER Lamp 

2) Biologicals are the new class of medicines with promising results