Skin Disorders Guide

Diagnostic Hallmarks

Distribution
(a) location of the lesions suggests a specific contactant
(b) unilateral or asymmetrical distribution suggests external causation
Shape of the lesions suggests a specific contactant to the clinician
Removal of the suspected contactant leads to resolution of the dermatitis
Positive patch test

Clinical Presentaion
The lesions of allergic contact dermatitis are quite different in appearance from those of irritant contact [...]

Diagnostic Hallmarks

Sun-exposed surfaces of the face, ears, bald scalp, hands, and arms
Lesions occur on visibly sun-damaged skin
Lesions occur primarily in fair-skinned people who tan poorly

Clinical Presentation
Clinically, actinc keratoses consist of little more than bits of scale adherent to sun-damaged skin, there is little in the way of underlying substance on palpation. Small lesions [...]

Categories of Pruritus
Patients with pruritus can be divided into avo major groups, those with and those without associated, readily visible skin disease. In either case, episodes of pruritus may occur spontaneously or may be precipitated by excessive skin dryness (xerosis), retained sweat, or psychologic factors such as anxiety or depression. Again, in either case, the [...]

Erylherna nodosurn commonly presents as a tender erythematous plaque simulating an area of cellulitis. A location on the “interior lower leg, stability in size, a chronic course, and a lack of rapid response to antibiotic therapy should suggest the possibility of erythema nodosum rather than cellulitis.Patients with severe acne frequently develop tender inflamed cystic lesions. [...]

The “attributes of lesions” represent the adjectives that are used to modify those nouns. In both verbal and written description it desirable first to pick an appropriate noun from the list of lesions and then to add as many modifiers as necessary to accurately complete the characterization of the lesion in question.
Margination
Margination is the [...]

Diagnostic Hallmarks

Distribution - pattern depends on the insect
Sudden onset
Spontaneous resolution in hours to days

Clinical Presentation
Most insect bites result in the development of nonscaling, dome-shaped, red papules 4 to 8 mm in size. A central punctum, if present, is diagnostic. Itching is usually, but not invariably, present. The papules often appear within minutes, [...]

Diagnostic Hallmarks

Distribution - face, upper trunk, and proximal arms
Central feeder vessel with arborizing telangiectatic vessels
Association with liver disease and hormones

Clinical Presentation
The central feeding arteriole is a macule (or very small papule) 1 to 2 mm in diameter. Multiple small telangiectatic vessels (”legs”) radiate outward from the central vessel. Pressure on the central [...]

Several of the nonvesicular viral exanthems including rubella and rubeola are characterized by the presence of red macules 1 to 2 cm in diameter. The occurrence of such lesions in the setting of characteristic clinical symptoms and signs allows for correct diagnosis. Roseola (exanthem subitum), recently found to be caused by human herpesvirus 6 is [...]