PHARMACY TECHNICIAN CHAPTER TWENTY ONE

The Skin Epidermis—outermost layer of skin Contains melanocytes, where pigment is stored Thinnest skin layer

The Skin (cont.) Dermis—middle layer of skin tissue Contains fibroblasts responsible for secreting collagen and elastin Contains immune cells, hair follicles, blood vessels, and sweat and oil glands Location of the sensory receptors for touch, pain, heat, and cold Helps maintain body temperature Subcutaneous layer (hypodermis)—deepest layer of skin Outermost part of the muscle is located here Stores fat tissue Contains connective tissue

Functions of the Skin Acts as a mechanical barrier to infection Provides for the sense of touch Regulates body temperature Excretes waste products and salt from the body Synthesizes vitamin D (with sunlight) for the absorption of calcium

Diseases of the Skin—Rash Area of red, inflamed skin, or a group of red spots Caused by irritation, allergy, infection, or defects in the skin’s structure Pharmaceutical treatment: antihistamines, topical corticosteroids

Diseases of the Skin—Eczema Skin inflammation with red, pimple-like bumps Characterized by itching, blistering, or oozing areas that progress to scaly, brownish, or thickened skin Pharmaceutical treatment: topical immunomodulators Chronic immune disorder Specific immune cells become overactive and release excessive amounts of proteins called cytokines Causes inflammation and painful, often disfiguring plaques Pharmaceutical treatment: topical steroids, oral antibiotics, immunosuppressants

Diseases of the Skin—Viral Infection Occurs when a virus infects the inner layers of the skin Examples: herpes simplex, warts, shingles Pharmaceutical treatment: anti-inflammatory steroids or antihistamines

Diseases of the Skin—Bacterial Infection Occurs when bacteria penetrate the skin and cause opportunistic infection Most common bacterial infections: staphylococci, streptococci, and pseudomonas If left untreated, may spread throughout the body, causing systemic infections Examples: cellulitis, impetigo, folliculitis Pharmaceutical treatment: oral antibiotics

Diseases of the Skin Fungal Infection Occurs when harmless fungi gain entry into the skin Usually external, affecting the skin, hair, and nails Examples: athlete’s foot, jock itch, ringworm Pharmaceutical treatment: topical antifungals Acne Bacterial infection Results in an overproduction of sebum, which clogs the hair follicles Categorized as noninflammatory or inflammatory Pharmaceutical treatment: topical antiseptics

Diseases of the Skin Cellulitis Acute, deep infection of the connective tissue Accompanied by inflammation Pharmaceutical treatment: oral or IV antibiotics Parasitic Infestations Caused by insects or worms that burrow into the skin to live and/or lay eggs Examples: scabies, lice Pharmaceutical treatment: antiparasitic topical agents

Parasitic infestation—head lice.

Diseases of the Skin—Tumors and Cancerous Growths Occur when skin cells multiply or reproduce faster than normal Cells without mutation are noncancerous or benign Tumors or skin growths with mutation are cancerous or malignant Pharmaceutical treatment: topical chemotherapeutic agents, immunomodulators, NSAIDs for precancerous actinic keratosis

Basal cell carcinoma. Malignant melanoma.

Diseases of the Skin—Pigmentation Disorders Skin color is determined by the amount of melanin produced by the body Hypopigmentation—loss of skin pigmentation Example: vitiligo Hyperpigmentation—excess skin pigmentation Examples: freckles, age or “liver” spots Pharmaceutical treatment: none