Chapter 13: Dermatology

Clinical assessment is enhanced through specialized examination techniques such as the Darier sign for mast cell activation, the Auspitz sign for vascular responses in psoriasis, and the Nikolsky sign indicating intraepidermal separation in pemphigus vulgaris, alongside diagnostic modalities including diascopy, potassium hydroxide preparation, Wood's light evaluation, and tissue biopsy. The chapter systematically addresses eczematous disorders including contact dermatitis in both irritant and allergic forms, atopic dermatitis as a chronic relapsing condition with multifactorial pathogenesis, and seborrheic and nummular variants managed through topical steroids and phototherapy. Papulosquamous conditions encompass lichen simplex chronicus arising from chronic scratching behaviors, psoriasis as a chronic inflammatory disease with nail involvement, and self-limited conditions like pityriasis rosea and lichen planus. Vesiculobullous diseases, particularly autoimmune conditions such as pemphigus vulgaris and bullous pemphigoid, require systemic immunosuppressive therapy. Papulopustular inflammatory disorders include acne vulgaris and rosacea managed with topical and systemic agents, alongside serious conditions like Stevens-Johnson syndrome and toxic epidermal necrolysis that demand emergency intervention. The chapter covers localized infections including bacterial pyogenic infections and parasitic infestations, neoplastic conditions ranging from benign keratoses to melanoma and nonmelanoma skin cancers requiring surgical and systemic interventions, and chronic wounds including diabetic, stasis, arterial, and pressure ulcers necessitating comprehensive wound management. Finally, the chapter addresses hair, nail, and pigmentation disorders such as alopecia, onychomycosis, and vitiligo with condition-specific therapeutic approaches tailored to underlying pathophysiology.