NMS Q&A Family Medicine

310 NMS Q&A Family Medicineand lotions toward the drying end. When the etiology is anoninfectious inflammatory process as in contact dermatitis,not as a part of a chronic connective tissue disease,glucocorticoids are a legitimate therapeutic modality. Systemicglucocorticoids are not as effective on the thickerparts of the dermal organ (as opposed to being moreeffective on the glabrous skin, e.g., volar forearm, face, andgenitalia). In this case, the presence of diabetes is relativelycontraindicated because of predictable certain rocketinglevels of blood sugar during their use. In the latter cases,topical glucocorticoids are not only more effective but arealso fraught with complications involving skin atrophyand local striae formation if the preparation is too potentor used for too long a period. Thus, in this instance, themild agent hydrocortisone at the low concentration of 1%is chosen rather than a potent preparation such as a fluorinatedointment.9. The answer is E. Dermatitis herpetiformis is a vesiculatingdisease of the skin that makes its onset during the3rd and 4th decades and then is generally lifelong. Thevesicles are approximately the size of those found in varicellaand occur on the extensor surfaces of the bodyreferred to in the vignette. The vesicles are often not presenton examination because of the excoriations (whichare due to the intense itching and scratching) that obliteratethem. However, most patients readily describe thevesicles that recur and lead to scratching. The disease isgenetically transmitted, with a strong prevalence in peoplewith human leukocyte antigen types HLA-B8 and HLA-DR3. Diagnosis requires an index of suspicion suggestingskin biopsy that shows immunoflourescently visibleimmunoglobulin A deposits at the tips of dermal papillae.Therapy with oral dapsone, given as 25 to 50 mg daily, isdramatically effective. An alternative, sulfapyridine, forthose with allergy or intolerance to the foregoing, orcolchicine, in usual dosages has been found to be effective.Neither psoriasis nor discoid lupus is pruritic. Discoidlupus occurs in isolated, usually single, plaques. Scabies,although pruritic to a degree rivaling dermatitis herpetiformis,does not produce vesicles and tends to affect theaxillae and web spaces. Food allergy typically causes urticariaand virtually never vesicles.10. The answer is D. Seborrheic keratosis is typically welldemarcated, often pigmented and rough on the surfacewithout inflammatory signs. It has been described by dermatologistsas waxy and “stuck on” in appearance as if itcould be peeled off. Squamous cell carcinoma nearlyalways displays an inflammatory appearance and an irregularbuildup of keratin. Squamous cell carcinoma may bepigmented but occurs on sun-exposed parts of the body.Actinic keratosis occurs in the regions where squamouscell carcinoma is found, is less inflammatory, and is lesslikely to be pigmented. Melanoma also is likely to be irregularat the edges or early manifesting inflammatory focicentrally. Basal cell carcinoma displays a very slow progression,often pearly appearance, and sometimes centralulceration. In any of the foregoing situations, a biopsy isnecessary for confirmation.11. The answer is B. Psoriatic arthritis occurs in about45% of patients with psoriasis and may precede the onsetof dermal manifestations of psoriasis by varying amountsof time. As an inflammatory arthritis (psoriasis is an autoimmunedisease), this arthritis exhibits morning stiffnessand gelling after periods of inactivity. What differentiatespsoriatic arthritis from rheumatoid arthritis is its asymmetricalinvolvement of hands and feet and that it includesthe DIP as well as PIP joints and occasionally knees andhips. The pinpoint-type pitting of fingernails is a hallmarkof psoriasis, occurring in 30% of patients. The DIP jointsof the hands are involved in osteoarthritis in people in their6th and 7th decades (Heberden nodes). Traumatic arthritisis mentioned as a red herring, given the patient’s history ofbasketball activity and presumed history of numerousstoving injuries. Traumatic arthritis is a form of osteoarthritisand thus is noninflammatory, manifesting no significantstiffness. Gout would not be seriously consideredin this age group without more classic presentations suchas great toe metatarsophalangeal joint involvement.12. The answer is A. Pityriasis rosea occurs without a discernibleherald patch in about 50% of cases. Secondarysyphilis should be considered in all cases of pityriasis roseabut is unlikely in a monogamous man. (Nevertheless, thestandard of care dictates a serologic test for syphilis in allcases.) Contact dermatitis is unlikely in a situation inwhich the affected areas of the skin are in contact withdifferent fabrics. Nummular eczema will not occur inunreachable areas such as the upper back; classically, itaffects the antecubital and popliteal fossae among otherplaces. Food allergies follow a waxing–waning course,depending on meals and their times of ingestion.13. The answer is E. Intermittent intense sun exposureconstitutes a greater skin cancer risk than daily less intenseexposure over a period of years. This is apparent to peoplewho have experienced sunburns to the trunk and legs onnumerous occasions during their youth and young adultyears and daily but less intense exposure to the head, neck,and forearms. In the late middle years, actinic changes arefound to a much greater degree on the thighs and lowerlegs than in the head, neck, and forearms, the latter areashaving received many more hours of sun exposure thanthe intermittently and more intensely exposed areas. Thebest prevention is total blockade and shade. Next would besunscreens that block both UVA and UVB; next would besunscreens that block UVB. Avoidance of the most directhours of sunlight (10 AM to 4 PM , according to the U.S.Preventive Services Task Force) is advisable but does notconfer secure protection against skin aging and cancer.