Chapter 16 Lesson 16.2 Lunula melanin Paronychium pore sebaceous gland sebum squamous epithelium stratified stratum, strata stratum corneum subcutaneous layer Journal question: What types of glands in the skin are responsible for the condition called acne? Where are these glands located, and how do they produce acne?

Objectives Describe lesions, symptoms, and pathological conditions that relate to the skin.

Cutaneous Lesions Label the lesions What is the definition of a lesion? Which of these lesions are similar but are differentiated by size? Which lesions involve the dermis layer?

Cutaneous Lesions (cont’d) Review the lesions What is the definition of a lesion? Which of these lesions are similar but are differentiated by size? Which lesions involve the dermis layer?

Signs and Symptoms Alopecia: absence of hair where it normally grows What are some causes of alopecia? Are there any treatments for baldness? Are they successful? Another form of alopecia is a result of trichotillomania, or obsessive hair-pulling.

Signs and Symptoms (cont’d) Ecchymosis: blue-black marks on the skin What can cause ecchymosis? What is the treatment?

Signs and Symptoms (cont’d) Petechia: small pinpoint hemorrhage Use the pictures as examples. Ask students whether they have ever been diagnosed with any of the skin conditions mentioned. What diseases are associated with these symptoms? What is pruritus? What is purpura?

Signs and Symptoms (cont’d) Urticaria: acute allergic reaction with red, round wheals on skin What is the common term for urticaria? Have students discuss their experiences (or that of someone they know) with hives. What causes hives? How long do they last?

Abnormal Conditions Acne: papular and pustular eruption of skin with increased production of sebum What is the medical term for a blackhead? Why are adolescents so prone to acne? Myths and reality. Are over-the-counter treatments effective?

Abnormal Conditions (cont’d) Burns: injury to tissue due to heat, chemical, electric shock, lightning or radiation. Image shows (A) Second degree burn and (B) Third degree burn. Go over the different degrees of burns and use a chart with the layers of the skin to demonstrate how deep the burns go. What percentage of body burn results in death? Why?

Abnormal Conditions (cont’d) Cellulitis: diffuse acute infection of skin Eczema: inflammation of skin with erythematous and papulovesicular lesions caused by allergy Exanthematous viral diseases: rash due to virus (for example, rubella) Gangrene: death of tissue with loss of blood supply Which of these diseases is/are common in children? Why? What are other diseases that are similar to eczema? Are they all treated in the same way?

Abnormal Conditions (cont’d) Impetigo: contagious pyoderma caused by staph or strep Psoriasis: chronic recurrent dermatosis with silver gray scales that itch Scabies: parasitic (tiny mites) and infectious pruritus Scleroderma: chronic and progressive disease of skin with hardening of connective tissue Which of these diseases are NOT contagious? Which disease may worsen if the patient experiences anxiety?

Abnormal Conditions (cont’d) Systemic lupus erythematosus (SLE): inflammatory disease of collagen in skin, joints, and internal organs What are the current thoughts about the origin of SLE? How is it treated? Where have we discussed it before because of other organ systems it affects?

Abnormal Conditions (cont’d) Tinea: infection of the skin caused by fungus Tinea corporis Tinea unguium What is tinea? (fungal infection of skin or nails, that is, ringworm, athlete’s foot)

Abnormal Conditions (cont’d) Vitiligo: Loss of pigment in areas of skin Vitiligo What is vitiligo? (loss of pigment in areas of skin causing milk-white patches)