Porth's Essentials of Pathophysiology, 4e

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Integumentary Function

U N I T 1 3

B. Persons with psoriasis are instructed to refrain from rubbing or scratching the lesions. Explain the rationale for these instructions. C. Among the methods used in the treatment of psoriasis are the use of topical keratolytic agents and corticosteroid skin preparations. Explain how these two different types of agents exert their effect on the plaque lesions. 4. During the past several decades there has been an alarming increase in the incidence of skin cancers, including malignant melanoma, that has been attributed to increased sun exposure. A. Explain the possible mechanisms whereby ultraviolet radiation promotes the development of malignant skin lesions. B. Cite two important clinical signs that aid in distinguishing a dysplastic nevus from a malignant melanoma. 1. Likeness LO. Common dermatologic infections in athletes and return-to-play guidelines. J Am Osteopath Assoc. 2011;111(6):373–379. 2. Wolff K, Johnson RA, Saavedra AP, eds. Fitzpatrick’s Color Atlas and Synopsis of Clinical Dermatology . 7th ed. Chicago, IL: McGraw-Hill; 2013:607–610. 3. Goodheart HP. Goodheart’s Photoguide to Common Skin Disorders . Philadelphia, PA: Wolters Kluwer Health | Lippincott Williams & Wilkins; 2009:167–187. 4. DermNet NZ. Mycology of Dermatophyte Infections . 2013. Available at: http://www.dermnetnz.org/fungal/mycology.html. Accessed September 25, 2013. 5. Patel GA, Schwartz RA. Tinea capatitis: still an unsolved problem? Mycoses. 2011;51:183–188. 6. Grover C, Arora P, Manchada V. Comparative evaluation of griseofulvin, terbenafine, and fluconazole in the treatment of tinea capitis. Int J Dermatol. 2012;51:455–458. 7. Gonzalez U, Seaton T, Bergus G, et al. Systemic antifungal therapy for tinea capitis in children: a summarized Cochrane review. Clin Exp Dermatol. 2010;36:826–827. 8. Graham LVD, Elewski BE. Recent updates in oral terbenafine: its use in onychomycosis and tinea capitis in the US. Mycoses. 2011;54:e679–e685. 9. Wolff K, Johnson RA, Saavedra AP, eds. Fitzpatrick’s Color Atlas and Synopsis of Clinical Dermatology . 7th ed. Chicago, IL: McGraw-Hill; 2013:591. 10. Wolff K, Johnson RA, Saavedra AP, eds. Fitzpatrick’s Color Atlas and Synopsis of Clinical Dermatology . 7th ed. Chicago, IL: McGraw-Hill; 2013:524. 11. Wolff K, Johnson RA, Saavedra AP, eds. Fitzpatrick’s Color Atlas and Synopsis of Clinical Dermatology . 7th ed. Chicago, IL: McGraw-Hill; 2013:534. 12. Goodheart HP. Goodheart’s Photoguide to Common Skin Disorders . Philadelphia, PA: Wolters Kluwer Health | Lippincott Williams & Wilkins; 2009:140–150. 13. Goodheart HP. Goodheart’s Photoguide to Common Skin Disorders . Philadelphia, PA: Wolters Kluwer Health | Lippincott Williams & Wilkins; 2009:155–161. R E F E R E N C E S

SUMMARY CONCEPTS

R E V I EW E X E R C I S E S 1. The mother of a 7-year-old boy notices that he is scratching his head frequently. On close examination she notices a grayish, round, and roughened area where the hair has broken off. Examination by the child’s pediatrician produces a diagnosis of tinea capitis. A. Explain the cause of the infection and propose possible mechanisms for spread of this infection in school-age children, particularly during winter months. B. Referring to Chapter 14, explain the preference of the superficial mycoses (dermatophytoses) for the skin-covered areas of the body. C. What methods are commonly used in the diagnosis of superficial fungal infections? 2. A 75-year-old woman presents with severe burning pain and a vesicular rash covering a strip over the rib cage on one side of the chest. She is diagnosed with herpes zoster or shingles. A. What is the source of this woman’s rash and pain? B. Explain the dermatomal distribution of the lesions. 3. Psoriasis is a chronically recurring papulosquamous skin disorder, characterized by circumscribed red, thickened plaques with an overlying silvery-white scale. A. Explain the development of the plaques in terms of epidermal cell turnover. ■■ Some skin problems occur in specific age groups. Common in infants are diaper rash, prickly heat, and cradle cap. Nevi, hemangiomas, and port- wine stains may be present at birth. Infectious childhood diseases that are characterized by rashes include roseola infantum, rubella, rubeola, and varicella. Vaccines are available to protect against rubella, rubeola, and varicella. ■■ With aging, there is thinning of the dermis and the epidermis, diminution in subcutaneous tissue, loss and thickening of blood vessels, and slowing of hair and nail growth. Dry skin is common among the elderly, becoming worse during the winter months. Among the skin lesions seen in the elderly are skin tags, keratoses, lentigines, and vascular lesions.