Dermatology Exam Master | 188 Case studies
Correct answer:
1. Case
Seborrheic dermatitis
A 20-year-old Caucasian
woman presents to the hos- Explanation
pital with a 2-month history This patient most probably has seborrheic dermatitis. Itis char-
of itchiness of her scalp. On acterized by greasy scales over the scalp. It may also be visible
examination you note greasy along the hairline, on the eyebrows, in the external auditory
yellowish scales on her scalp canals, in the nasolabial folds, and over the sternum. There may
and eyebrows. be some pruritus.
Question Hand eczema is characterized by erythema, dryness, cracking,
What is the most likely diag- and edema of the skin of the hands. It is a chronic condition,
nosis? which is aggravated by frequent immersion of hands in water
A) Hand eczema and detergents.
B) Seborrheic dermatitis
C) Atopic dermatitis Atopic dermatitis is characterized by chronic pruritic lesions
D) Nummular dermatitis marked by exacerbations and remissions. There is a personal
E) Pompholyx or family history of asthma, allergic rhinitis, food allergies, or
eczema. In the acute phase, they may present with erythema-
tous patches, weeping, and crusted plaques. In the chronic
phase, they present with hyperpigmented lichenified lesions.
It commonly attects the face, neck, wrists, antecubital, and
popliteal fossae.
Nummular dermatitis is characterized by chronic coin-shaped,
crusted lesions, which are usually pruritic. They commonly ap-
pear on the trunk and extensor surfaces of the extremities,
especially the pretibial areas.
Pompholyx is characterized by scaling and deep-seated vesi-
cles on the palms, fingers, and soles, which are pruritic. There
may also be erythema and scaling.
, Dermatology Exam Master | 188 Case studies
2. Case Correct answer:
A 7-year-old boy presents Skin scraping with immersion oil
with a 3-day history of intense
pruritus on his wrists, fingers, Explanation
and antecubital fossae. It be- Skin scraping with immersion oil is the confirmatory test for
gan on his fingers and has scabies, which is the most likely diagnosis.
moved proximally. According
Wood lamp inspection consists of shining ultraviolet light on
to his mother, they are raised
the skin, looking for fluorescence indicative of such diseases
red eruptions and some have
as erythrasma, fungal infections, and sclerosis. Skin scraping
scabbed over. She states he
with KOH is helpful in diagnosing fungal infections of the skin.
has never had this before and
Punch biopsies are more invasive, and they are used for deeper
it is keeping him up at night. genital area. The itching in-
He recently started at a new
school.
Question
What procedure would be
most helpful in confirming
your diagnosis?
A) Skin scraping with immer-
sion oil
B) Woods lamp inspection
C) Skin scraping with KOH
D) Punch biopsy
E) Skin culture and gram stain
3. Question
A 23-year-old man presents
with unbearable itching in his
, Dermatology Exam Master | 188 Case studies
skin lesions. Skin culture and Gram stain are not
helpful in the diagnosis of scabies; they are used
for suspected bacterial or fungal infections.
Correct answer:
Scabies
Explanation
The correct answer is scabies because intense
pruritis, es-
, Dermatology Exam Master | 188 Case studies
creases in intensity at night. pecially at night, with excoriated papules and characteristic
He admits to several recent burrows or raised tunnels under the skin are a typical presen-
sexual encounters with differ- tation.
ent people in the past month.
Skin exam reveals multiple ex- Tinea cruris is a fungal infection and can also be intensely
coriated papules and burrows pruritic but does not cause the dermatologic manifestations
with surrounding inflamma- noted above.
tion. What is the most likely
Pediculosis pubis, an arthropod, is another cause of pruritis but
diagnosis?
does not cause the dermatologic manifestations noted above,
A) Tinea cruris
and typically the lice and their nits are seen on examination.
B) Pediculosis pubis
C) Scabies
Molluscum contagiosum and HPV are caused by viruses, are
D) Molluscum contagiosum
not pruritic lesions, and do not present as excoriated papules
with burrows.
4. Question Correct answer:
A 15-year-old boy presents Urticaria
to the office with his mother
with a complaint of constant Explanation
itching and burning on his Urticaria is chronic or acute and is characterized by wheals and
arms and thighs for 2 weeks. papules. Itching and prickling sensations are constant. Both
His mother admits to giving sexes are attected equally, and it's often seen in childhood or
him acetaminophen without teen years. The presenting areas are the arms, legs, thighs, and
relief. The patient is taking waist. The most common cause is an allergy to medications,
no other medications. On clin- foods, or physical agents. The symptoms usually disappear
ical exam, there are multi- the most likely diagnosis?
ple 2-cm wheals with a few
small papules on his thighs
and forearms. They are red
and slightly raised. What is
Correct answer:
1. Case
Seborrheic dermatitis
A 20-year-old Caucasian
woman presents to the hos- Explanation
pital with a 2-month history This patient most probably has seborrheic dermatitis. Itis char-
of itchiness of her scalp. On acterized by greasy scales over the scalp. It may also be visible
examination you note greasy along the hairline, on the eyebrows, in the external auditory
yellowish scales on her scalp canals, in the nasolabial folds, and over the sternum. There may
and eyebrows. be some pruritus.
Question Hand eczema is characterized by erythema, dryness, cracking,
What is the most likely diag- and edema of the skin of the hands. It is a chronic condition,
nosis? which is aggravated by frequent immersion of hands in water
A) Hand eczema and detergents.
B) Seborrheic dermatitis
C) Atopic dermatitis Atopic dermatitis is characterized by chronic pruritic lesions
D) Nummular dermatitis marked by exacerbations and remissions. There is a personal
E) Pompholyx or family history of asthma, allergic rhinitis, food allergies, or
eczema. In the acute phase, they may present with erythema-
tous patches, weeping, and crusted plaques. In the chronic
phase, they present with hyperpigmented lichenified lesions.
It commonly attects the face, neck, wrists, antecubital, and
popliteal fossae.
Nummular dermatitis is characterized by chronic coin-shaped,
crusted lesions, which are usually pruritic. They commonly ap-
pear on the trunk and extensor surfaces of the extremities,
especially the pretibial areas.
Pompholyx is characterized by scaling and deep-seated vesi-
cles on the palms, fingers, and soles, which are pruritic. There
may also be erythema and scaling.
, Dermatology Exam Master | 188 Case studies
2. Case Correct answer:
A 7-year-old boy presents Skin scraping with immersion oil
with a 3-day history of intense
pruritus on his wrists, fingers, Explanation
and antecubital fossae. It be- Skin scraping with immersion oil is the confirmatory test for
gan on his fingers and has scabies, which is the most likely diagnosis.
moved proximally. According
Wood lamp inspection consists of shining ultraviolet light on
to his mother, they are raised
the skin, looking for fluorescence indicative of such diseases
red eruptions and some have
as erythrasma, fungal infections, and sclerosis. Skin scraping
scabbed over. She states he
with KOH is helpful in diagnosing fungal infections of the skin.
has never had this before and
Punch biopsies are more invasive, and they are used for deeper
it is keeping him up at night. genital area. The itching in-
He recently started at a new
school.
Question
What procedure would be
most helpful in confirming
your diagnosis?
A) Skin scraping with immer-
sion oil
B) Woods lamp inspection
C) Skin scraping with KOH
D) Punch biopsy
E) Skin culture and gram stain
3. Question
A 23-year-old man presents
with unbearable itching in his
, Dermatology Exam Master | 188 Case studies
skin lesions. Skin culture and Gram stain are not
helpful in the diagnosis of scabies; they are used
for suspected bacterial or fungal infections.
Correct answer:
Scabies
Explanation
The correct answer is scabies because intense
pruritis, es-
, Dermatology Exam Master | 188 Case studies
creases in intensity at night. pecially at night, with excoriated papules and characteristic
He admits to several recent burrows or raised tunnels under the skin are a typical presen-
sexual encounters with differ- tation.
ent people in the past month.
Skin exam reveals multiple ex- Tinea cruris is a fungal infection and can also be intensely
coriated papules and burrows pruritic but does not cause the dermatologic manifestations
with surrounding inflamma- noted above.
tion. What is the most likely
Pediculosis pubis, an arthropod, is another cause of pruritis but
diagnosis?
does not cause the dermatologic manifestations noted above,
A) Tinea cruris
and typically the lice and their nits are seen on examination.
B) Pediculosis pubis
C) Scabies
Molluscum contagiosum and HPV are caused by viruses, are
D) Molluscum contagiosum
not pruritic lesions, and do not present as excoriated papules
with burrows.
4. Question Correct answer:
A 15-year-old boy presents Urticaria
to the office with his mother
with a complaint of constant Explanation
itching and burning on his Urticaria is chronic or acute and is characterized by wheals and
arms and thighs for 2 weeks. papules. Itching and prickling sensations are constant. Both
His mother admits to giving sexes are attected equally, and it's often seen in childhood or
him acetaminophen without teen years. The presenting areas are the arms, legs, thighs, and
relief. The patient is taking waist. The most common cause is an allergy to medications,
no other medications. On clin- foods, or physical agents. The symptoms usually disappear
ical exam, there are multi- the most likely diagnosis?
ple 2-cm wheals with a few
small papules on his thighs
and forearms. They are red
and slightly raised. What is
