Psoriasis
Background
- Often begins in the 2nd or 3rd decade of life
- Chronic and relapsing
- Types:
- Chronic and relapsing
1:plaque: also known as psoriasis vulgaris, makes up about 90 percent of cases. It typically presents as red patches with white scales on top. Areas of the body most commonly affected are the back of the forearms, shins, navel area, and scalp. 2:guttate: Guttate psoriasis has drop-shaped lesions. 3:inverse: Inverse psoriasis forms red patches in skin folds 4:pustular: Pustular psoriasis presents as small non-infectious pus-filled blisters 5:erythrodermic: Erythrodermic psoriasis occurs when the rash becomes very widespread, and can develop from any of the other types. Fingernails and toenails are affected in most people with psoriasis at some point in time. This may include pits in the nails or changes in nail color.
Triggers
- Stress
- Trauma
- Drugs: NSAIDs, B-blockers
Clinical Features
Psoriasis before and after treatment.
- Well-demarcated erythematous plaques and papules with silvery white scales
- Epidermal hyperproliferation
- Commonly found on the trunk, scalp, nail pitting, and extensor surfaces
- Auspitz sign: plaque removal reveals pinpoint-bleeding areas
- Associated with psoriatic arthritis, especially in nail involvement
Differential Diagnosis
Other Rash
- Acute generalized exanthematous pustulosis
- Allergic reaction
- Aphthous stomatitis
- Atopic dermatitis
- Coxsackie
- Dermatitis herpetiformis
- Exfoliative erythroderma
- Impetigo
- Pellagra
- Pityriasis rosea
- Serum Sickness
- Tinea capitus
- Tinea corporis
- Vitiligo
Management
- Ketoconazole 2% shampoo
- Hydrocortisone cream 1%
- Systemic steroids should be avoided due to the risk of developing rebound or induction of pustular psoriasis
See Also
References
- Uptodate
- Hess MR, Hess SP: Skin Disorders Common on the Trunck, in Tintinalli JE, Kelen GD, Stapczynski JS (eds): Emergency Medicine, A Comprehensive Study Guide, ed 7. New York, McGraw-Hill, 2011, (Ch) 249:p 1653-1654