Epidermis = outermost layer of skin

Dermis = the deeper layer , blood vessels provide nutrients and oxygen, regulate heat, and remove waste products. Nerves also form a network in the dermis to provide the sensations of heat, cold, pain, and touch.

Nails are made of keratin

Herpes zoster causes shingles ; causes chickenpox in children and causes zoster (shingles) in adults;characterized by painful lesions that follow the course of a spinal nerve

Lyme disease is transmitted to humans by the bite of an infected tick; characteristic bull’s-eye skin rash is a common sign

Tinea unguium = involves the fingernail or toenail and is characterized by white patches in the nail, difficult to treat because the fungus hides under the nail; can destroy the entire nail, causing it to thicken, overgrow, turn white, and become brittle

Body lice often occur in individuals with poor hygiene practices

Squamous cell carcinoma can appear as a firm, red nodule with crusts or a slightly elevated plaque/sore that does not heal or bleeds easily might be a symptom of this cancer

Lentigo = small brown spot occurring on the face, neck, and back of the hands of older adults/ commonly called liver spots (not due to aging but to years of overexposure to the sun)

Abrasions = common mechanical trauma caused by scraping away the skin surface = Abrasions (also called friction burns or rug burns)

Verrucae = warts, a chronic skin condition, usually occur in multiples that can differ in size, shape, and appearance (more commonly affect children)

Erythema= skin redness

Elephantiasis is caused by a parasitic worm that enters the lymphatic system and causes obstruction of drainage and accumulation of fluids

Biopsy may help diagnose nodules and chronic lesions

Common warts predominantly appear on the hands and fingers of children ( these are contagious); Plantar warts appear on the sole of the foot

Furuncle = small abscess occurring in the tissues of the skin, commonly called a boil

Methicillin-resistant Staphylococcus aureus (MRSA)= a strain of bacteria that is resistant to the antibiotics commonly used to treat staphylococcal infections

Avulsion = when a portion of skin or appendage is pulled or torn away/usually occur when tissue is caught up in some type of machinery

Heat exhaustion = heat prostration

Heatstroke is more serious than heat exhaustion-temperature rises above 105°F, and the skin is red, hot, and dry with no perspiration