1. Which supplement is most likely to reduce the gastrointestinal side effects of methotrexate?
a. Folate
b. Vitamin A
c. Niacinamide
d. Vitamin D
2. Netherton syndrome is typically characterized by the presence of all of the following clinical features, except
a. Ichthyosis
b. Hair shaft abnormality
c. Atopy
d. Dental malformations
3. By what age are most infantile hemangiomas generally apparent?
a. At birth
b. 2-3 weeks old
c. 6-8 weeks old
d. 4-6 months old
4. Which of the following conditions is least likely to exhibit Koebner phenomenon?
a. Psoriasis
b. Lichen planus
c. Atopic dermatitis
d. Vitiligo
5. Which layer of the epidermis is also referred to as the squamous cell layer?
a. Stratum germinativum
b. Stratum granulosum
c. Stratum corneum
d. Stratum spinosum
6. Upon initial diagnosis of which of the following conditions is referral to ophthalmology most important to monitor for serious ocular sequelae?
a. Sarcoidosis
b. Neurofibromatosis
c. Pemphigus vulgaris
d. Dermatomyositis
7. How is a pathergy test performed?
a. The skin is stroked firmly with a blunt object.
b. Gentle pressure is applied to flaccid bullae.
c. The skin is pricked with a sterile needle.
d. A pencil eraser is twisted against the skin.
8. Regarding the use of eosin staining in dermatopathology, which of the following statements is true?
a. Eosin stains the nuclei of keratinocytes.
b. Eosin is most commonly used with hematoxylin.
c. Eosin is a basic dye.
d. Eosin results in a purplish blue color.
9. A young adult man presents with thick, cone-shaped, oyster shell-like skin lesions on his scalp and trunk. What is the most appropriate terms for this condition?
a. Guttate psoriasis
b. Pustular psoriasis
c. Rupioid psoriasis
d. Erythrodermic psoriasis
10. When considering systemic antipruritic treatment, which of the following medications is contraindicated during lactation?
a. Cetirizine
b. Diphenhydramine
c. Fexofenadine
d. Doxepin
Answers
1. a. Folate. Methotrexate is an analog of folate that produces immunosuppressive effects by inhibiting folate metabolism. Because of this mechanism of action, daily supplementation with 1-5 mg of folate has been shown to reduce the nausea, vomiting, stomatitis, oral ulcerations, elevated transaminases, and mild myelosuppression that can be associated with methotrexate treatment. Folate (unlike folinic acid) does not compete with methotrexate for cellular uptake and can be given on the same day as methotrexate without compromising the efficacy of the methotrexate.
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. d. Dental malformations. Netherton syndrome is a rare autosomal recessive disorder that is characterized by ichthyosis, atopy, and a structural hair shaft abnormality. Affected infants may present with generalized erythroderma at birth and have feeding problems, poor absorption, and failure to thrive. The associated ichthyosis (ichthyosis linearis circumflexa) appears as generalized hyperkeratosis and polycyclic and serpiginous erythematous plaques with a characteristic, migratory, double-edged scale at the margins. The atopic dermatitis may be pruritic and cause lichenification. These cutaneous features result in an abnormal skin barrier that allows increased percutaneous absorption and associated risk of systemic toxicities from topical medications. Asthma, severe food allergies, and marked elevations of serum IgE may also occur. The associated hair shaft abnormality is referred to as trichorrhexis invaginata or "bamboo hair." The distal hair segment is telescoped into the proximal one and forms a ball-and-socket appearing deformity that is apparent with microscopic examination. Only 20%-50% of the hairs may be affected, most commonly the eyebrows. This abnormality may not be present at birth and may disappear with age.
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.
3. b. 2-3 weeks old. Most infantile hemangiomas first become evident within the first 2-3 weeks of life and potentially continue to grow until around 9-12 months old. Most growth generally occurs within the first 5 months of life, and in those lesions that continue to grow beyond this point, the growth rate is markedly slower. Occasionally, lesions exhibit a proliferative phase that lasts for more than 1 year and sometimes as long as 18-24 months. Deep hemangiomas tend to have a delayed onset of growth and a longer growth phase. It is estimated that complete involution of infantile hemangiomas occurs at a rate of 10% per year, such that 30% have involuted by 3 years old, 50% by 5 years old, and 90% by 9-10 years old. Involution begins with a color change from bright red to dull red, purple, or gray. Residual telangiectasias, atrophy, scarring, or fibrofatty masses may persist after involution.
Paller, A. S., & Mancini, A. J. (2011). Hurwitz clinical pediatric dermatology (4th ed.). New York, NY: Elsevier Saunders.
4. c. Atopic dermatitis. Koebner phenomenon refers to the appearance of new skin lesions on areas of cutaneous injury in otherwise healthy skin. Psoriasis, lichen planus, and vitiligo are conditions that are commonly reported to exhibit Koebner phenomenon. The resulting lesions are often linear in shape because they follow the route of cutaneous injury. In addition to lacerations and excoriations, the precipitating trauma may be in the form of bites, burns, cryotherapy, or pressure injuries. Chemical irritation, phototherapy, and high-energy radiation have also been reported to cause Koebner phenomenon. The reason this phenomenon occurs is unclear, although it appears that injury to both the epidermis and dermis is necessary. A pseudo-Koebner response can occur because of the seeding of an infectious agent in an area of trauma, such as what can happen with warts and molluscum. Individuals who experience Koebner phenomenon are at risk for this occurrence with future trauma and should be counseled to avoid cutaneous injury.
New Zealand Dermatological Society Incorporated. (2015). The Koebner phenomenon. Retrieved from http://www.dermnetnz.org/reactions/koebner.html
5. d. Stratum spinosum. Within the epidermis, the stratum germinativum, also known as the basal layer, contains a single layer of column-shaped keratinocytes that attach to the basement membrane zone. Overlying the basal layer is the squamous cell layer or stratum spinosum. This layer is 5-10 cells thick and is composed of a variety of cells that differ in shape, structure, and subcellular properties depending on their location. Suprabasal spinous cells are polyhedral in shape with a rounded nucleus, and these cells enlarge and flatten as they are pushed toward the surface of the skin. The most superficial layer of the epidermis containing living cells, the granular layer, or stratum granulosum, is composed of large, flattened keratinocytes. The stratum corneum, also referred to as the cornified or horny layer, provides mechanical protection to the underlying epidermis and a barrier to prevent water loss and invasion by foreign substances. The corneocytes of this layer have lost their nuclei during terminal differentiation and are considered dead.
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.
6. a. Sarcoidosis. About 12% of individuals with sarcoidosis have ocular involvement, most commonly in the form of anterior, intermediate, or posterior uveitis. However, visual loss from sarcoidosis can occur with or without ocular symptoms. Therefore, all sarcoid patients should be referred to ophthalmology upon initial diagnosis and have regular follow-up. Some cases of ocular pemphigus vulgaris have been reported in the literature and involve nonscarring conjunctivitis without long-term visual sequelae. Referral to ophthalmology should be given to patients with pemphigus vulgaris who experience ocular symptoms. Dermatomyositis and neurofibromatosis are not commonly associated with serious ocular complications. Lisch nodules (pigmented iris hamartomas) are common in Neurofibromatosis type 1 and can be useful in diagnosing this condition, although they rarely lead to symptoms or complications.
Bolognia, J. L., Jorizzo, J. L., & Schaffer, J. V. (2012). Dermatology (3rd ed.). St. Louis, MO: Elsevier/Mosby.
Horner, M. E., Abramson, A. K., Warren, R. B., Swanson, S., & Menter, M. A. (2014). The spectrum of oculocutaneous disease: Part I. Infections, inflammatory and genetic causes of oculocutaneous disease. Journal of the American Academy of Dermatology, 70(5), 795.e1-795.e25.
7. c. The skin is pricked with a sterile needle. Pathergy is an exaggerated skin injury occurring after minor trauma such as a bump, bruise, or needle stick injury. When performing a skin pathergy test, multiple pricks are made into the forearm using a sterile needle. The pricked area is observed over the next few days. A positive pathergy test is present if a papule, pustule, or ulceration is observed at the site of the needle prick. Pathergy testing is often positive in Behcet disease, pyoderma gangrenosum, and Sweet disease. Pathergy can also be present in individuals with inflammatory bowel disease as well as in healthy individuals. Because of the nonspecific and insensitive nature of pathergy testing, it is not often utilized in clinical settings. Asboe-Hansen sign refers to the application of gentle pressure on intact bullae, which forces the fluid to spread under the adjacent skin. When a twisting or rubbing motion causes intact epidermis to shear away from the underlying dermis, this is termed Nikolsky sign. To test for Darier's sign, the skin is stroked or scratched to determine if urtication occurs.
James, W. D., Berger, T. G., & Elston, D. M. (2011). Andrews' diseases of the skin: Clinical dermatology (11th ed.). Philadelphia, PA: Saunders/Elsevier.
New Zealand Dermatological Society Incorporated. (2011). Pathergy. Retrieved from http://www.dermnetnz.org/reactions/pathergy.html
8. b. Eosin is most commonly used with hematoxylin. Because most cells are colorless and transparent, histological sections need to be stained in some way to make the cells visible. The most commonly used routine stain is called H&E because it contains the two dyes hematoxylin and eosin. Eosin is an acidic dye that stains basic (or acidophilic) structures red or pink. This is also sometimes termed "eosinophilic." Hematoxylin is actually a dye called hematein that is used in combination with aluminum ions that make this stain act as a basic dye. It is used to stain acidic (or basophilic) structures a purplish blue. Thus, when H&E stains are used, the nucleus and parts of the cytoplasm that contain RNA stain purple, and the rest of the cytoplasm stains pink.
Faculty of Biological Sciences, University of Leeds. (2016). What is H&E? Retrieved from http://histology.leeds.ac.uk/what-is-histology/H_and_E.php
9. c. Rupioid psoriasis. The term "rupioid" has been used to describe well-demarcated, cone-shaped plaques with thick, dark, lamellate, and adherent crusts on the skin that somewhat resemble oyster or limpet shells. The term is based on the Greek word "rhupos," which means dirt or filth. Rupioid manifestations have been clinically observed in a variety of diseases, including rupioid psoriasis, reactive arthritis, disseminated histoplasmosis, keratotic scabies, secondary syphilis, and photosensitive skin lesions in association with aminoaciduria. To diagnose the underlying infectious or inflammatory disease, a skin biopsy and blood test for syphilis may be necessary. Treatment often requires systemic therapy because of the extensive hyperkeratosis associated with rupioid lesions.
Chung, H. J., Marley-Kemp, D., & Keller, M. (2014). Rupiois psoriasis and other skin diseases with rupioid manifestations. Cutis, 94, 119-121.
10. d. Doxepin. Doxepin is excreted in human breast milk, and although the transfer is small, studies show that exposed infants experienced poor suck, poor swallowing, muscle hypotonia, and emesis. There is one report of an infant developing dangerous sedation and respiratory arrest because of doxepin exposure via breast milk, and because of this, the World Health Organization classifies doxepin as incompatible with breastfeeding. Because first-generation antihistamines (such as diphenhydramine) easily cross the blood-brain barrier and cause sedation, there is theoretically an increased risk of sudden infant death syndrome in breastfed infants whose mothers take these medications. However, the published literature fails to support this association. Multiple studies have also shown that first-generation antihistamines do not affect milk production. Some mothers who take first-generation antihistamines have reported perceived irritability, drowsiness, or decreased sleep in their exposed neonate, but there are no reports of infants who needed medical attention related to this exposure. Because of these concerns, first-generation antihistamines should be used with caution in lactating mothers. Second-generation antihistamines are preferred because they do not cross the blood-brain barrier as readily and therefore have minimal sedating effects. The transfer of cetirizine, fexofenadine, and loratadine across the blood-brain barrier is reported to be as low as 3.0%, 0.1%, and 1.1% of the maternal dose, respectively. However, if mothers consume high doses of these medications, exposed infants should be monitored for signs of excessive irritability, jitteriness, and drowsiness.
Murase, J. E., Heller, M. M., & Butler, D. C. (2014). Safety of dermatologic medications in pregnancy and lactation: Part II. Lactation. Journal of the American Academy of Dermatology, 70(3), 417.e1-417.e10.