The color, shape, size and texture of lesions are used to diagnose skin diseases.

Corticosteroids are steroid hormones synthesized by the outer layer (cortex) of the adrenal gland. The effects of corticosteroids are numerous and widespread.

Urticaria is a hypersensitivity skin disorder characterized by the development of rashes i.e. localized redness & swelling on the skin. The swelling may also extend into the lower parts of the skin.

The natural defenses of the skin prevent the development of infection. There are two types of natural defenses – present on the skin surface and beneath the barrier layer.

The normal skin flora exists in harmony without causing any lesions on the skin. However, they may become pathogenic or new organisms may invade the skin. Imbalance between the body’s natural defense mechanism and heavy implantation of pathogenic bacteria can result in pyoderma - a bacterial infection of the skin.

Fungi are recognized as an independent group of organisms, which differ from plants in structure, nutrition, and reproduction.  They are responsible for a significant number of skin disorders.

Acne is a self-limiting disease of the skin involving the pilosebaceous unit. The condition usually occurs in adolescence and is characterized by lesions of varying severity (comedones, papules, pustules, and superficial pus filled cysts). In very severe conditions, extensive scarring can follow.
Acne vulgaris is an extremely common skin condition and affects almost 80% of adolescents and young adults aged 11-30 yrs. It has a negative impact on their emotional and social well-being. Though initially called a physiological process, it is better regarded as a disease due to its inflammatory component and the disfigurement it produces.

Melanin is the principal determinant of skin color. The constitutive melanin (genetically determined) and inducible melanin (due to sunlight) determine the skin color.

Ultra-Violet Rays from the sun can damage skin depending on the type of the human skin. The damaging effect of absorbed radiation depends on the skin type i.e., the susceptibility of human skin to UVR-induced acute and chronic damage is related to skin type. Skin type varies according to the ability of individuals to produce pigment and sensitivity to sun.

Dry skin is a very common problem both in healthy individuals and in patients with skin diseases. It can occur in association with age, in response to the environment, and in genetically based disorders. Chronically dry skin eventually may become wrinkled, brittle, flaky or leathery, adding years to a person’s appearance.

Loss of hair is termed as effluvium. This loss of hair over a period of time gives rise to a condition known as alopecia. The term alopecia is derived from Latin meaning “baldness”.