Psoriasis presents as silvery, scaly papules and plaques, sharply demarcated and salmon colored, commonly on the knees and elbows, driven by CD8 and CD4 T cells with dendritic cells.

Explore scleroderma as a systemic autoimmune disease causing skin fibrosis and visceral involvement. Recognize esophageal dysmotility, pulmonary hypertension, renal crisis, and diffuse versus limited forms, including crest syndrome.

Isotretinoin reduces sebum production to treat severe acne. It shrinks sebaceous glands, is highly teratogenic, and requires liver and lipid monitoring.

Trace acne pathophysiology from sebaceous unit plug to inflammation driven by Propionibacterium acnes and free fatty acids. Androgens increase sebum, with mild to severe forms, treated by isotretinoin or alternatives.

Erythema multiforme forms blisters and red to purple lesions in various shapes, most commonly target lesions, and arises from infections or drugs; treatment removes the trigger and reassesses for resolution.

Angiosarcoma is a malignant vascular cancer often presenting late, treated with surgery, radiation, and chemotherapy, and linked to prior radiation, mastectomy with lymphedema, sun-exposed skin, or liver metastasis.

Identify cherry hemangiomas as common benign 2–4 mm reddish papules often on aging skin. Diagnosis is clinical; removal via electrodissection, liquid nitrogen, or laser is possible, though recurrence is high.

Identify atopic dermatitis as eczema, a type one hypersensitivity with IgE, facial onset in infancy, axillary involvement later, and links to asthma, allergic rhinitis, and flowering gene–related skin barrier dysfunction.

Identify neurogenic ulcers from peripheral sensory loss, especially on heels, metatarsal heads, or sacral areas; ulcers are deep with inward edges, no pain, and show claw toes or Charcot joints.