1. Which of the following statements is not characteristic of primary Raynaud phenomenon?
a. Bilateral involvement
b. Negative antinuclear antibody
c. Dilated nail fold capillaries
d. Normal erythrocyte sedimentation rate
2. What is the most common location for squamous cell carcinoma among Blacks?
a. Lower extremities
b. Genitals
c. Upper extremities
d. Face and ears
3. When considering the use of lidocaine in an individual with mastocytosis, which of the following statements is true?
a. Systemic and local use of lidocaine should be avoided whenever possible.
b. Systemic and local use of lidocaine can stimulate mast cell degranulation if not administered with epinephrine.
c. Local injections of lidocaine with sodium bicarbonate should be avoided, but systemic lidocaine can be used safely.
d. Systemic lidocaine should be avoided, but local injections of lidocaine can be used safely.
4. All of the following terms are commonly used to describe the hypomelanotic macules of tuberous sclerosis except
a. thumbprint macules.
b. spider macules.
c. confetti macules.
d. ash-leaf macules.
5. Which infectious agent is most commonly responsible for the development of tinea amiantacea?
a. Staphylococcus aureus
b. Malassezia furfur
c. Pseudomonas aeruginosa
d. Trichophyton tonsurans
6. Nevus of Ito generally occurs in which anatomic region?
a. Periorbital
b. Supraclavicular
c. Perioral
d. Lumbosacral
7. Which of the following statements is true regarding the pruritus associated with Hodgkin's lymphoma?
a. It is the presenting symptom in most cases.
b. It initially involves the trunk and upper extremities.
c. Its intensity is not associated with disease severity.
d. It is resistant to traditional pruritus therapies.
8. What is the primary function of Merkel cells?
a. Facilitate T-cell-mediated immunity
b. Enhance tactile sensitivity
c. Engulf foreign invaders via phagocytosis
d. Secrete lipids into the intercellular spaces
9. Which of the following best describes the initial clinical appearance of a fixed drug eruption?
a. Edematous, erythematous plaque with tiny papulovesicles
b. Purpuric, targetoid lesion with central clearing
c. Sharply demarcated, erythematous and edematous plaque
d. Erythematous, scaly patch with poorly circumscribed borders
10. When injecting hyaluronic acid fillers, the Tyndall effect can result in the appearance of
a. matted telangiectasias.
b. granuloma formation.
c. mottled hypopigmentation.
d. blue papules or nodules.
Answers
1. c. Dilated nail fold capillaries. Primary Raynaud phenomenon is characterized by vasospastic attacks precipitated by exposure to cold or emotional stimuli. The attacks are typically bilateral, and the affected digits first become pale, cold, and numb. As blood flow is restored, the digits often appear cyanotic and then bright red. Upon examination, the pulses in the affected extremities should be symmetric, and the nail fold capillaries should not reveal any abnormalities. If the nail fold capillaries are dilated or tortuous, this is suggestive of connective tissue disease, such as scleroderma. Laboratory testing should reveal a negative antinuclear antibody test and normal erythrocyte sedimentation rate. If these tests are elevated, this may indicate an underlying condition causing secondary Raynaud phenomenon.
Goldsmith, L. A., Katz, S. I., Gilchrest, B. A., Paller, A. S., Leffell, D. J., & Wolff, K. (2012). Fitzpatrick's dermatology in general medicine (8th ed.). New York, NY: McGraw-Hill Medical.
2. a. Lower extremities. Squamous cell carcinoma (SCC) is the most commonly diagnosed skin cancer among Blacks. The greatest predisposing factors for developing SCC within this population include chronic scarring and/or inflammatory processes such as hidradenitis suppurativa, lupus erythematosus, scars caused by chemical and thermal burns, skin ulcers, and sites of previous radiation. For this reason, SCC on Black individuals is most commonly found in areas that are not typically exposed to the sun. The lower limbs are the most common site of involvement, followed by the head and neck and then the genitals. The mortality rate of SCC in Blacks is as high as 29%, secondary not only to delays in diagnosis and treatment but also to the more aggressive biologic behavior of SCC in this population. In Blacks, SCC that develops within a chronic scarring process tends to be more aggressive and is associated with a 20%-40% risk of metastasis. In contrast, the rate of metastatic transformation of sun-induced SCC in Blacks is approximately 1%-4%. Although most patients with primary SCC have a very good prognosis, the 10-year survival rate is less than 20% in patients with regional lymph node metastasis and less than 10% in patients with distant metastasis.
Agbai, O. N., Buster, K., Sanchez, M., Hernandez, C., Kundu, R. V., Chiu, M., [horizontal ellipsis] Lim, H. W. (2014). Skin cancer and photoprotection in people of color: A review and recommendations for physicians and the public. Journal of the American Academy of Dermatology, 70(4), 748-762.
3. d. Systemic lidocaine should be avoided, but local injections of lidocaine can be used safely. A number of systemic anesthetic agents, including lidocaine, d-tubocurarine, metocurine, etomidate, thiopental, succinylcholine hydrochloride, enflurane, and isoflurane have been directly or indirectly implicated in precipitating anaphylactoid reactions in patients with mastocytosis. Local injections of lidocaine (with or without sodium bicarbonate and with or without epinephrine) can be used safely in these patients. It has also been reported that propofol, vecuronium bromide, and fentanyl are safe alternative systemic anesthetics for patients with mastocytosis.
Bolognia, J. L., Jorizzo, J. L., & Rapini, R. P. (2007). Dermatology (2nd ed.). St. Louis, MO: Elsevier/Mosby.
4. b. Spider macules. Most patients with tuberous sclerosis have more than one hypomelanotic macule, and some have over 100. The most common configuration is the small (<2 cm) "thumbprint"-shaped macule, which is found in up to 80% of individuals with tuberous sclerosis. "Ash-leaf" macules are rounded at one end and tapered at the other and can range in size from 1 to 12 cm in size. The term "confetti macules" refers to scores of 1- to 2-mm hypopigmented guttate macules, especially on the extremities. These lesions occur in less than 5% of affected individuals but are probably the most specific for tuberous sclerosis.
Bolognia, J. L., Jorizzo, J. L., & Schaffer, J. V. (2012). Dermatology (3rd ed.). St. Louis, MO: Elsevier/Mosby.
5. a. Staphylococcus aureus. Tinea amiantacea, also called pityriasis amiantacea, presents with thick, asbestos-like (amiantaceous), shiny scales on the scalp. The silvery white or dull gray crusting may be localized or, less often, generalized over the entire scalp, and the proximal parts of the hairs are matted together by the laminated crusts. The cause is most often a secondary staphylococcus infection occurring in seborrheic dermatitis or psoriasis. Treatment is focused on removal of the scale and crusts with shampoos that contain selenium sulfide, tar, or steroids with or without prior application of a peanut oil or keratolytic. With such debridement, the secondary infection usually resolves without the need for oral antibiotics.
James, W. D., Berger, T. G., & Elston, D. M. (2011). Andrews' diseases of the skin: Clinical dermatology (11th ed.). Philadelphia, PA: Saunders/Elsevier.
6. b. Supraclavicular. Nevus of Ito occurs predominantly in more darkly pigmented individuals, especially Blacks and Asians. It favors the distribution of the posterior supraclavicular and cutaneus brachii lateralis nerves, which encompass the supraclavicular, scapular, and deltoid regions. It is generally characterized by a confluence of individual macules varying from pin-head size to several millimeters in diameter, which give an overall appearance of an irregularly demarcated mottled patch. The coloration varies from shades of tan and brown to gray, blue, black, and purple because of melanin-producing melanocytes in the dermis. The overall lesion size may be a few centimeters, or there may be extensive involvement. Nevus of Ito may occur as an isolated lesion or in association with an ispilateral or bilateral nevus of Ota.
James, W. D., Berger, T. G., & Elston, D. M. (2011). Andrews' diseases of the skin: Clinical dermatology (11th ed.). Philadelphia, PA: Saunders/Elsevier.
7. d. It is resistant to traditional pruritus therapies. Pruritus is the presenting symptom of Hodgkin's lymphoma in about 30% of patients and can precede development of other symptoms by several months or up to 5 years. The pruritus is generally described as burning and initially involves the lower extremities. The intensity of the pruritus increases with age and disease severity. The pruritus associated with Hodgkin's disease is resistant to traditional pruritus therapies but improves with treatment of the lymphoma.
Garcia-Albea, V., & Limaye, K. (2012). The clinical conundrum of pruritis. Journal of the Dermatology Nurses' Association, 4(2), 97-105.
8. b. Enhance tactile sensitivity. Merkel cells are oval-shaped, slow-adapting, Type I mechanoreceptors located in sites of high tactile sensitivity such as the digits, lips, regions of the oral cavity, and outer root sheath of the hair follicle. Relatively small deformations of adjoining keratinocytes are stimulus enough to cause Merkel cells to secrete a chemical signal that generates an action potential in the adjoining afferent neuron, which relays the signal to the brain. High concentrations of Merkel cells result in smaller and more densely packed receptive fields and thus higher tactile resolution and sensitivity.
Kolarsick, P.A. J., Kolarsick, M. A., & Goodwin, C. (2011). Anatomy and physiology of the skin. Journal of the Dermatology Nurses' Association, 3(4), 203-213.
9. c. Sharply demarcated, erythematous and edematous plaque. Classic fixed drug eruption (FDE) appears in the form of one or a few round, sharply demarcated erythematous and edematous plaques, sometimes with a dusky violaceous hue, central blister, or detached epidermis. The lesions can arise anywhere on the body but favor the lips, face, hands, feet, and genitalia. The first incidence of FDE generally develops 1-2 weeks after exposure to the responsible medication. With subsequent exposures, the eruption occurs in the same site within 24 hours. The lesions fade over several days and often leave a postinflammatory brown pigmentation. In the nonpigmenting variant of FDE, erythematous edematous plaques appear, often in the girdle region, that are characteristically quite large in diameter (>10 cm) and heal with no residual. There is also a rare linear variant of FDE that may be confused with linear lichen planus.
Bolognia, J. L., Jorizzo, J. L., & Schaffer, J. V. (2012). Dermatology (3rd ed.). St. Louis, MO: Elsevier/Mosby.
10. d. Blue papules or nodules. The Tyndall effect results in the appearance of blue papules and nodules and occurs when hyaluronic acid fillers are inappropriately implanted into the superficial dermis or epidermis. The lesions appear blue because blue light waves have a higher frequency than red light waves and are more easily scattered. When light hits the surface of the skin with superficially placed hyaluronic acid particles, the particles cause the light waves to be reflected. Because of the increased scatter, blue is the predominant color that emerges. The most common treatment for this complication is the use of hyaluronidase, which is an off-label treatment for this condition.
Torres, O., Pilcher, M. F., & Rogachefsky, A. (2014). Hyaluronidase to treat the Tyndall effect. The Dermatologist, 22(10), 29-31.