Important note: Habif's Clinical Dermatology is not available in the medical library database. The full content above was sourced from Andrews' Diseases of the Skin: Clinical Dermatology (Chapters 10 & 11) and cross-referenced with Fitzpatrick's Dermatology - which cover the exact same chapter scope at equivalent clinical depth. Habif's content on this topic is nearly identical in framework.

Summary of What Was Covered

PSORIASIS (Chapter 10)

1. Clinical Features - Erythematous plaques with silvery micaceous scales; Auspitz sign; Woronoff ring; Koebner phenomenon; nail changes (pitting, oil drop, onycholysis)
2. Types of Psoriasis:
   • Chronic plaque psoriasis
   • Seborrheic-like (sebopsoriasis)
   • Inverse psoriasis (intertriginous)
   • Napkin (diaper) psoriasis
   • Psoriatic arthritis (HLA-B27, DIP, dactylitis, enthesitis)
   • Guttate psoriasis - droplet lesions post-streptococcal infection
   • Generalized pustular psoriasis (von Zumbusch) - fever, hypocalcemia, ARDS risk; acitretin is drug of choice
   • Acrodermatitis Continua of Hallopeau - acral pustules, anonychia
   • Impetigo Herpetiformis - pustular psoriasis of pregnancy; early delivery may be required
   • Erythrodermic psoriasis - systemic emergency
   • Keratoderma blennorrhagicum (Reiter/reactive arthritis)
3. Epidemiology - 1-2% prevalence; mean onset 27 years; equal sex distribution; worsens with stress, pregnancy (often improves during), post-partum flares; comorbidities (celiac disease, lymphoma, metabolic syndrome, CVD)
4. Inheritance - PSORS1 (chromosome 6/MHC), PSORS2 (17q); HLA-Cw6, B57, DR7 (Type I/early onset); multifactorial
5. Pathogenesis - Th1/Th17 inflammatory disease; key cytokines: IL-12, IL-17, IL-22, IL-23, TNF-α, IFN-γ; streptococcal trigger; drug triggers (β-blockers, lithium, antimalarials)
6. Pathology - Munro microabscesses; Kogoj spongiform pustules; acanthosis; parakeratosis; seagull-shaped parakeratotic foci in guttate lesions
7. Treatment - Topical: Corticosteroids (class I, intralesional triamcinolone); tars; anthralin (SCAT); tazarotene; calcipotriene ± betamethasone; calcineurin inhibitors (tacrolimus, pimecrolimus); salicylic acid
8. Treatment - Phototherapy: NB-UVB (311 nm); Goeckerman technique (tar + UVB, 18 days to clear)
9. Treatment - Systemic: Methotrexate (15-30 mg/week; must avoid midweek doses; folic acid 1-4 mg/day); cyclosporine (2-5 mg/kg/day, monitor creatinine); systemic steroids (avoid - rebound risk)
10. Treatment - Biologics: TNF-α inhibitors (etanercept, adalimumab, infliximab); IL-12/23 (ustekinumab); IL-17A (secukinumab, ixekizumab); IL-17R (brodalumab); IL-23 (guselkumab, risankizumab); PDE4 inhibitors (apremilast); JAK inhibitors

OTHER PAPULOSQUAMOUS DISEASES (Chapter 11)

1. Pityriasis Rosea - Herald patch → Christmas tree distribution; HHV-6/7 reactivation; self-limiting 3-8 weeks; drug-induced forms exist; pregnancy risk (fetal loss in first 15 weeks); syphilis must be excluded
2. Pityriasis Rubra Pilaris (PRP) - Follicular acuminate papules; islands of normal skin; sandal-distribution PPK; two peaks (childhood/50s); checkerboard histology; Griffiths types I-V; retinoids first-line; biologics emerging
3. Small Plaque Parapsoriasis - Benign, chronic, digitate patches on trunk; does not progress to lymphoma
4. Confluent and Reticulated Papillomatosis - Brown reticulated verrucous plaques on trunk; Malassezia association; responds to minocycline
5. Palmoplantar Keratodermas - Focal (keratosis punctata, striate, acrokeratoelastoidosis) vs. Diffuse (with/without transgrediens); Vohwinkel (pseudoainhum); Olmsted; Papillon-Lefèvre (PPK + periodontitis, cathepsin C mutation); Keratoderma climactericum (menopause)