Chronic Psoriasis

Description

Posterior trunk skin is shown with multiple erythematous plaques topped by adherent silvery scale, distributed across the upper back and extending laterally over the scapular regions toward the posterior deltoids and proximal arms. Lesions cluster on either side of the midline over the thoracic spine and spread inferiorly toward the lumbosacral area above the waistband, a common pattern for chronic plaque psoriasis. Normal intervening skin remains visible, helping the borders and thickness of each plaque read clearly against the plain background. Scale thickness is obvious. Chronic plaque psoriasis reflects immune mediated epidermal hyperproliferation, so the raised, sharply marginated plaques and micaceous scale are the teaching points in this posterior view, where scratching and friction often accentuate disease via the Koebner phenomenon. Location over the back and proximal upper limbs also aligns with extensor surface involvement and helps separate psoriasis from seborrheic dermatitis (scalp and central face) or tinea corporis (annular plaques with peripheral scale). Screening for psoriatic arthritis matters here, because patients with long standing cutaneous burden frequently report inflammatory back pain or peripheral joint swelling, and body surface area involvement influences escalation from topical corticosteroids and vitamin D analogs to phototherapy or systemic agents (methotrexate, apremilast, biologics targeting TNF, IL-17, or IL-23). Look for nail pitting in clinic. Use this asset in dermatology modules to teach morphology (plaque, scale, erythema) and distribution, in primary care or rheumatology education to support recognition and referral thresholds, and in patient facing materials that explain chronicity and treatment pathways. Anatomical accuracy verified by SciePro's Medical Advisory Board.