Lichen simplex chronicus Clinical features Lichen simplex chronicus (LSC; also known as “neurodermatitis”) is a common secondary skin condition characterized by the development of thickened plaques with accentuated skin lines (i.e., lichenification). LSC is caused by chronic scratching or rubbing.…
Seborrheic keratoses Layla Kazemi and Afton Chavez Clinical features Seborrheic keratoses (SKs) are common benign skin lesions found in nearly all older individuals. They typically begin to appear during the fourth decade of life and then continue to develop throughout…
Acne Payal Shah and Nikita Lakdawala Clinical features Acne is most commonly located on the face, neck, back, upper chest, and upper arms where pilosebaceous units are most densely concentrated. Acne most commonly affects adolescents. Adult women have a predisposition…
Pityriasis alba Elizabeth Dupuy and Preeti Jhorar Clinical features Pityriasis alba is a benign inflammatory skin condition that presents with poorly circumscribed hypopigmented oval or round macules, patches, or thin plaques. Pityriasis alba is generally asymptomatic; patients may seek medical…
Melasma Casey Abrahams and Afton Chavez Clinical features Melasma is also known as “chloasma” or, colloquially, the “mask of pregnancy.” It is characterized by light to dark-brown or brown-gray patches with irregular borders that appear primarily on the face (…
Arthropod bites Campbell Stewart Clinical features Arthropods are responsible for many dermatologic complaints, including bites, stings, and infestations. They can also be vectors for numerous systemic and life-threatening diseases. The clinical manifestations of arthropod bites vary greatly depending on which…
Intertrigo Shivani Sinha, Gloria Lin, and Katalin Ferenczi Clinical features Intertrigo is an inflammatory condition commonly found in the intertriginous skin folds and flexures. It can be caused by multiple different conditions within the inflammatory and infectious categories. Many healthcare…
Hand dermatitis—with a specific focus on irritant contact dermatitis, allergic contact dermatitis, and dyshidrotic eczema Clinical features Hand dermatitis is extremely common because the hands are exposed to many environmental chemicals and irritants. The severity of hand dermatitis ranges dramatically…
Atopic dermatitis—trunk and extremities Clinical features The American Academy of Dermatology (AAD) has developed atopic dermatitis (AD) criteria that are useful in evaluating patients for AD. The three essential criteria (pruritus, typical AD pattern, and chronic/relapsing course) should be used…
Atopic dermatitis—face Clinical features Atopic dermatitis (AD; often referred to by patients as “eczema”) is a chronic inflammatory skin condition characterized by pruritus and pruritic, ill-defined, red, scaly papules and plaques that predominantly affect flexural surfaces (e.g., antecubital fossa, popliteal…