Psoriasis

Diagnosis: Psoriasis

Psoriasis

Clinical Presentation

Psoriasis

Clinical History

Submitted by Shahbaz A. Janjua. Originally posted March 10, 2010.

Treatment

See case discussion.

Differential Diagnosis

• Eczema/atopic dermatitis • Seborrheic dermatitis • Lichen planus • Pityriasis rosea • Tinea corporis • Secondary syphilis • Mycosis fungoides • Nummular eczema

Key Learnings

• Immune-mediated disease driven by Th17/IL-23 axis • Auspitz sign: pinpoint bleeding when scale is removed (dilated capillaries in dermal papillae) • Koebner phenomenon: lesions develop at sites of trauma • Nail involvement in ~50%: pitting, oil drop sign, onycholysis, subungual hyperkeratosis • Psoriatic arthritis develops in ~30% — screen regularly (CASPAR criteria) • Metabolic syndrome, cardiovascular disease, and depression are major comorbidities • Biologic therapy has revolutionized treatment — IL-17 and IL-23 inhibitors achieve PASI 90/100 in many patients • Histology: regular acanthosis, Munro microabscesses, dilated capillaries in dermal papillae, diminished granular layer

Tags: psoriasis, shahbaz a. janjua