| A complete physical examination should always be performed. Many skin diseases are manifestations of systemic diseases, eg, hypothyroidism, systemic lupus erythematosus. (See also
miscellaneous systemic dermatoses,
Miscellaneous Systemic Dermatoses: Introduction.) A good dermatologic examination requires very close inspection of the entire hair coat and skin under strong lighting; flashlights may be necessary to examine the skin of large animals. It is important to examine the ventrum of the animal, where many primary lesions and cutaneous parasites are found. |
| Clinical lesions are described in a variety of ways. Gross lesions can be described as focal, multifocal, or diffuse in distribution, followed by a description of the affected region (eg, mucocutaneous, truncal). On closer inspection, lesions may be further described as primary or secondary. Primary lesions include macules or patches (nonelevated areas of discoloration); papules or plaques (elevated lesions, the latter coalescing); pustules, vesicles, or bullae (fluid-filled
lesions); wheals (flat-topped, steep-walled, solid elevations of the skin arising from histamine release); or nodules or tumors (large solid elevations of the skin). Secondary lesions include epidermal collarettes (late stage of a pustule), scars, excoriation (areas of self-trauma), erosions or ulcers (loss of the epidermis), fissures, lichenification (increased thickening and hyperpigmentation of the skin), and calluses. Some lesions may be either primary or secondary, depending on
the etiology of the disease. These include alopecia, scale, crusts, follicular casts (plugging of hair follicles with visible keratin), comedos (blackheads), and pigmentary changes. |
