Internal-Medicine

Answers: 30–49 49
40. (E) A macule is a flat, colored lesion not raised
above the surface of the surrounding skin. It is
less than 1 cm in diameter. A patch differs from
a macule only in size, being greater than 1 cm
in diameter. (Kasper, p. 283)
41. (C) A KOH preparation is useful when performed
on scaling skin lesions, when a fungal
etiology is suspected. The scraped scales are
placed on a microscope slide, treated with one
or two drops of KOH solution, and examined
for hyphae, pseudohyphae, or budding yeast.
A Tzanck smear is a cytologic technique for the
diagnosis of herpes virus infection from vesicles,
and diascopy is to assess whether a skin
lesion will blanch with pressure. (Kasper, p. 286)
42. (D) Impetigo is a superficial bacterial infection
of skin caused by group A beta-hemolytic
streptococci or Staphylococcus aureus.
It is characterized by superficial pustules
that rupture, resulting in a honey-colored crust.
The bullous variant is more likely staphylococcal
in origin. Treatment requires improving
hygiene and soaking the crust, as well as oral
antibiotics. (Wolff, pp. 588–589)
43. (E) Localized areas of vitiligo can be seen in
numerous primary skin disorders. It can also be
caused by systemic disorders such as sarcoidosis
and tuberculoid leprosy. In the latter
disorder, there is associated anesthesia,
anhidrosis, and alopecia of the lesions. Biopsy
of the palpable border will reveal granulomas.
(Wolff, p. 658)
44. (G) Scleroderma is characterized by typical
fibrotic and vascular lesions. These lesions may
be periungual telangiectasias that are found in
lupus erythematosus and dermatomyositis.
Another form of telangiectasia, mat telangiectasia,
is seen only in scleroderma. These lesions
are broad macules 2–7 mm in diameter. They
are found on the face, oral mucosa, and hands.
The nail beds of scleroderma patients often
reveal loss of capillary loops, with dilatation of
the remaining loops when examined under
magnification. (Wolff, p. 398)
45. (D) Drug reactions most frequently result in
papulosquamous reactions or diffuse erythroderma.
Sulfa drugs frequently cause erythroderma.
Other drugs commonly implicated
include penicillins, gold, allopurinol, captopril,
phenytoin, and carbamazepine. Fever,
eosinophilia, and interstitial nephritis frequently
accompany the erythroderma. (Kasper,
pp. 158–160)
46. (K) Hyperlipoproteinemia is frequently associated
with xanthomas, yellow-colored cutaneous
papules or plaques. Xanthomas associated with
hypertriglyceridemia are frequently eruptive;
these yellow papules have an erythematous
halo and are most frequently found on extensor
surfaces of the extremities and buttocks. (Wolff,
p. 450)
47. (I) The first exanthem of secondary syphilis is
always macular and faint. Later eruptions may
be papulosquamous and often involve the
palms and soles. Associated findings that help
make the diagnosis include annular plaques
on the face, nonscarring alopecia, condylomata
lata, mucous patches, lymphadenopathy,
malaise, fever, headache, and myalgia. (Wolff,
p. 917)
48. (J) Obesity is the most common cause of
acanthosis nigricans—a velvety, localized
hyperpigmentation. Other causes include gastrointestinal
malignancy and endocrinopathy
such as acromegaly, Cushing’s syndrome,
Stein-Leventhal syndrome, or insulin-resistant
diabetes. (Wolff, p. 86)
49. (A) Cancer chemotherapy most frequently
involves rapidly proliferating elements of the
skin, resulting in stomatitis and alopecia.
Bleomycin, hydroxyurea, and 5-fluorouracil
can cause dystrophic nail changes. Other skin
manifestations of cancer drugs include sterile
cellulitis, phlebitis, ulceration of pressure areas,
urticaria, angioedema, and exfoliative dermatitis.
The underlying malignancy often
makes diagnosis of skin disease more difficult.
(Wolff, p. 1011)