Dermatology

Question 1

A 1-month-old presents with erythema of the scalp with a greasy scalp.

What is the most likely diagnosis?

Answer 1

Seborrhea

It usually begins within the first 2 months of life. Most cases resolve in several weeks to months.

Question 2

Name the disease:

• X-linked
• Patterned blistering that follows the lines of Blaschko (the routes of embryonic cell migration) - the extremities most prominent
• Delayed eruption of teeth with peg- or cone-shaped teeth; commonly missing teeth as well
• Strabismus

Answer 2

Incontinentia Pigmenti

IP is an X-linked dominant disorder that is usually lethal in males. It often presents as a rash on an otherwise healthy baby girl. There are 4 different stages of skin findings, but all 4 stages may or may not appear. The blistering described is most commonly asked about on exams. The tooth findings are classic! Refer all patients with IP for dental, opthalmologic, and neurologic consultations.

Question 3

A newborn presents with small, whitish-yellow masses on either side of the raphe on the hard palate.

What are these masses?

Answer 3

Epstein Pearls

They are essentially intraoral milia. They require no treatment and will resolve spontaneously.

Question 4

A newborn presents with tiny, pinhead-sized, white papules that appear on the surface of sebaceous glands in the pilosebaceous follicles on the face.

What is the most likely diagnosis?

Answer 4

Milia

These tiny epidermal inclusion cysts generally resolve spontaneously over several months and require no treatment.

Question 5

What is the recommended treatment for a very large Mongolian spot on the buttocks area in an African-American infant?

Answer 5

None

Mongolian spots are present at birth and are seen in > 90% of African-American and Native American babies. They disappear or fade over 7-13 years. No therapy is necessary.

Question 6

Rash that is:

• Well-defined, brown-to-reddish plaque with some slight scaling in the axillae, groin, and toe webs
• Seen under the breasts of obese adolescent females
• Caused by Corynebacterium minutissimum
• Fluorescent bright red when illuminated with a Wood’s lamp

What is this disorder?

Answer 6

Erythrasma

Erythrasma is common in adolescents, especially in those who are obese. Treat with oral or topical erythromycin ± an “-azole” antifungal cream.

Question 7

What cancer do you worry about in a child who has a large, congenital melanocytic nevus?

Answer 7

Melanoma

The lifetime risk of developing melanoma within a large, congenital melanocytic nevus is 6–8%, with the highest risk during the first 5 years of life. The future risk of melanoma in small or medium congenital melanocytic nevi appears to be small, and malignant change is rare before puberty.

Question 8

You diagnose a boy in the first few weeks of life with X-linked recessive ichthyosis. What is associated with this disorder and should be checked for in this boy?

Answer 8

Undescended Testes with Underdeveloped Penis and Scrotum

X-linked recessive ichthyosis occurs in 1/2,000–6,000 boys and generally is apparent at birth or during the first few months of life. The scales are more pronounced compared to the autosomal dominant form. The trunk is involved, but not the palms and soles. It is caused by the absence of the microsomal enzyme steroid sulfatase. These GU abnormalities are common in this disorder, with an associated increased risk of testicular cancer. Treatment of the ichthyosis consists of regular bathing and using emollients and keratolytics.

Question 9

What type of ANA pattern is seen in children with cutaneous lupus erythematosus?

Answer 9

Speckled ANA

Cutaneous lupus is associated with the Ro/La (SS-A/SS-B) antigen, which causes a speckled ANA. Don’t forget that the Ro/La antigens can cross the placenta and cause congenital heart block in the neonate.

Question 10

A 5-year-old boy presents with:

• Frontal bossing
• Flat malar ridges and depressed nasal root
• Thin upper lip and large, “pouting” lower lip
• Small chin, prominent ears, pegged teeth
• Periorbital wrinkling
• Sweating is almost absent; however, he has frequent fevers and heat stress admissions.
• He has no secretions from his nose, eyes, or mouth.

What is the most likely diagnosis?

Answer 10

Hypohidrotic Ectodermal Dysplasia

Hypohidrotic ectodermal dysplasia is the most common form of ectodermal dysplasia and is X-linked recessive. Females may or may not be affected, depending on which X chromosome is activated.

Question 11

Name the disease:

• Autosomal dominant
• Due to loss of function mutations in the gene encoding filaggrin
• Occurs in the extensor surfaces of the extremities as fine, white scales with redness
• Thickened palms and soles also occur
• Rash improves in hot, humid climates and during the summer

Answer 11

Ichthyosis Vulgaris

Ichthyosis vulgaris is the most common ichthyosis, occuring in 1/250 people. Most commonly, the condition first manifests after 3 months of age. Treatment is irritant avoidance and use of emollients and keratolytic products.

Question 12

A 9-year-old girl with history of atopic dermatitis now presents with:

• Areas of hypopigmentation with a fine scale
• Most areas are on the cheeks and extensor extremities

What is the most likely diagnosis?

Answer 12

Pityriasis Alba

Pityriasis alba is common in school-aged children with atopic dermatitis and presents as described. It is more apparent on children with darker skin and in the summer because the affected skin does not tan normally.

Question 13

A child presents with a nevus of Ota. What future complications do you worry about in this child?

Answer 13

Ocular and Cutaneous Melanoma

Most common in African-American or Asian infants. They present as unilateral, irregularly speckled areas of bluish-gray discoloration on the face, specifically the periorbital area, temple, forehead, cheek, nose, or eye. Do yearly eye and skin exams looking for melanoma.

Question 14

A patient presents with small, grouped, freckle-like, cafe-au-lait spots measuring 1-4 mm in the axilla. What disease should you consider?

Answer 14

Neurofibromatosis Type 1

The lesions described are known as Crowe sign, which occurs in the axilla or groin. Crowe sign is among the major diagnostic criteria of NF1.

Question 15

Infants with port-wine stains of the lower extremities are at risk for what syndrome?

Answer 15

Klippel-Trenaunay Syndrome

KTS presents with a vascular malformation (often mixed capillary-venous-lymphatic) of an extremity, with soft tissue and/or limb overgrowth and varicose veins.

Question 16

What is a common organism that causes erythema Multiforme major (> 2 mucous membranes involved)?

Answer 16

Mycoplasma Infection

Question 17

A child has a herpes simplex skin infection and develops target-like lesions on the palms and soles. He now has mild mucous membrane involvement as well.

What is the most likely diagnosis?

Answer 17

Erythema Multiforme (EM)

EM consists of well-defined lesions that evolve into target shapes. Palms and soles are frequently involved and mucous membranes may be affected. The target-shaped lesions are pathognomonic for erythema multiforme and are characterized by a central blister or zone of necrosis/crusting. These fixed lesions last for several days before resolving spontaneously.

Question 18

Identify the disorder:

• Lesions are present at birth or within the first 3 weeks of life.
• Appear as small, 1-2 mm papules and pustules on the face and scalp
• No comedones

Answer 18

Neonatal Acne

Neonatal acne typically resolves spontaneously within the first 1–2 months of life. The etiology is controversial; some consider it to be a hypersensitivity reaction to Malassezia furfur.

Question 19

In a patient with extremely severe seborrhea, what diagnosis should you consider?

Answer 19

Langerhans Cell Histiocytosis

Consider this particularly if atrophy, ulceration, or petechiae are present. Send for skin biopsy to diagnose.

Question 20

What tumors do girls with Gorlin syndrome (basal cell nevus syndrome) tend to develop?

Answer 20

Ovarian Tumors

Gorlin syndrome is an autosomal dominant disorder caused by mutations of the “patched” gene that controls cell growth and patterning. These children develop basal cell carcinoma in childhood. Because this is a defect in tumor suppression, they have a tendency to develop ovarian tumors, as well as other malignancies, including medulloblastoma. Use traditional tumor-directed therapies. Patients also benefit from vismodegib, which is a targeted therapy that inhibits the hedgehog pathway (a signaling pathway that regulates cell differentiation and proliferation).

Question 21

According to the 2015 Red Book, should children be excluded from school or sent home early from school because of head lice?

Answer 21

No

“No-nit” policies requiring children to be free of nits before returning to school are not effective in preventing the spread of head lice. They are explicitly discouraged by the 2015 Red Book.

Question 22

What virus is the most common cause of erythema Multiforme?

Answer 22

Herpes Simplex Virus

EM is typically a reactive process to a viral illness, classically HSV. EM is subdivided into EM minor and EM major, the difference being that EM major has mucosal involvement and patients can be systemically ill.

Question 23

What presents as a ringworm-like lesion, but is not scaly and usually appears on the distal extremity?

Answer 23

Granuloma Annulare

GA is a benign skin disorder with unknown cause. It appears very much like ringworm, but there is no scale on the surface of the lesion as you would see with ringworm. It is generally asymptomatic and self-limited, disappearing within months to a few years.

Question 24

A 5-year-old has an eczematous rash in the antecubital fossa, popliteal fossa, and back of the neck. He also has double creases under the lower eyelids.

What is the most likely diagnosis to affect these skin areas?

Answer 24

Atopic Dermatitis

Atopic dermatitis has different presentations in different age groups. Infants have lesions most commonly on the cheeks and extensor surfaces of the extremities, with scalp and trunk involvement as well. Older children who can scratch more tend to present like the child described here. Adolescents present with continued flexural and chronic hand/foot dermatitis.

Question 25

What are the white blood cells found in the pustules of transient neonatal pustular melanosis (TNPM)?

Answer 25

Neutrophils

After the pustules rupture, the skin develops scaly, hyperpigmented macules of uniform size that may persist for months before resolving on their own. TNPM is seen in 2–5% of African American neonates.

Question 26

A 16-year-old boy presents with:

• History of a round ringworm-like lesion 1 week ago
• Subsequent development of small, oval, pruritic papulosquamous lesions, with the long axis parallel to skin folds and rib lines

What is the most likely diagnosis?

Answer 26

Pityriasis Rosea

Pityriasis rosea is common in children and adolescents. It often presents with the “herald patch” 1–2 weeks before the pruritic rash appears on the trunk. The latter rash commonly is described as a “Christmas tree” pattern. Treat the symptoms (the itching). Do not confuse this with pityriasis versicolor (a.k.a. tinea versicolor), which is a fungal infection due to Malassezia and requires antifungal therapy.

Question 27

Is poison ivy spread by fluid contained in the vesicular or bulbous lesions?

Answer 27

No

Poison ivy can only be spread by contact with the plant resin. If the patient or their clothes have not been washed and still contain the poison ivy resin, then it can spread that way!

Question 28

What syndrome should you suspect in an infant born with a large facial port-wine stain?

Answer 28

Sturge-Weber Syndrome

Sturge-Weber syndrome consists of an ipsilateral cerebral vascular malformation that can cause neurologic complications, including seizures, intellectual disabilities, contralateral hemiplegia, choroidal vascular anomalies, and glaucoma.

Traditionally, persons with port-wine stains along the CN 5 (1) distribution were felt to be at highest risk for Sturge-Weber syndrome. New literature (2013) shows that the facial vascular malformations of Sturge-Weber are the result of somatic mosaicism.

The majority of facial port-wine stains are not associated with Sturge-Weber syndrome.

Question 29

A newborn presents with an area of absence of skin on her head.

What is the most likely diagnosis?

Answer 29

Aplasia Cutis

Aplasia cutis congenita is a congenital absence of skin that usually occurs only in a small, localized area, most commonly on the scalp. ∼ 20% will have underlying skull abnormalities. If it occurs in multiple places on the scalp, look for trisomy 13.

Question 30

What is the skin condition that consists of red, very painful, warm nodules that appear on the shins and is associated with infection (TB, streptococci, fungal), drugs (oral contraceptives, sulfas, and penicillins), and inflammatory bowel disease in children?

Answer 30

Erythema Nodosum

EN is associated with sarcoidosis, but in children it is more commonly due to infection, drugs, or inflammatory bowel disease. It is often idiopathic, but the most common identifiable cause is streptococcal pharyngitis.

Question 31

A 5-month-old presents with a hemangioma that involves the orbit. What is the risk (high, low) of ocular complications?

Answer 31

High

Periorbital hemangiomas have ~ 80% risk of ocular complications, including astigmatism, amblyopia, refractive errors, and occasionally blindness.

Question 32

What are the white blood cells found in the pustules of erythema toxicum neonatorum?

Answer 32

Eosinophils

Erythema toxicum neonatorum is a common, self-limited condition occurring in the first few days of life; rarely is it present at birth. Increased levels of immunological and inflammatory mediators suggest it is an immunological reaction. It consists of small, pink pustules filled with eosinophils. It typically resolves spontaneously within the first week of life.

Question 33

What causes Stevens-Johnson syndrome (SJS)?

Answer 33

Severe Drug Reactions

SJS presents with skin sloughing and mucous membrane involvement. The most common culprits are sulfa antibiotics and the aromatic anticonvulsants (phenytoin, phenobarbital, or carbamazepine). Treatment consists of discontinuing the offending drug; monitoring for internal organ involvement; and supportive care in a hospital setting with skilled nursing, often in burn units.

Question 34

Identify the disorder:

• Absent at birth
• Appears at 3-4 months of age
• Papules and pustules with open and closed comedones distributed over the face
• More common in boys

Answer 34

Infantile Acne

It can be contrasted from neonatal acne based on the timing (infantile much later appearance) and the lesions (comedones in infantile). Infantile acne, unlike other lesions, requires therapy; usually with topical benzoyl peroxide or antibiotics. It is caused by androgenic stimulation of the sebaceous glands.

Question 35

Acrodermatitis enteropathica is due to deficiency of what mineral?

Answer 35

Zinc

Acrodermatitis enteropathica (zinc deficiency) can be an acquired or inherited disorder. The genetic form is an autosomal recessive disorder with impaired absorption of zinc from the intestine. Cutaneous manifestations include red, scaly patches in a periorificial distribution (i.e., mouth, anus). Patients also present with alopecia, failure to thrive, and diarrhea.

Question 36

A child presents with the following:

• Dandy-Walker syndrome
• Hemangioma that is large, involving the cervicofacial area, including cranial nerve V1
• Intracerebral arterial anomalies
• Coarctation if the aorta
• Micropthalmia

What is the syndrome presented here?

Answer 36

PHACES Syndrome

PHACES syndrome occurs with large, segmental facial hemangiomas.

• P—Posterior fossa abnormalities (Dandy-Walker)
• H—Hemangioma
• A—Arterial anomalies
• C—Cardiac defects, especially coarctation of the aorta
• E—Eye abnormalities (microphthalmia)
• S—Sternal defects/Supraumbilical raphe

Question 37

A child is given cephalosporin and develops target-like lesions on the palms and soles. He now has mucous membrane involvement as well. What is the most likely diagnosis?

Answer 37

Erythema Multiforme

It consists of well-defined lesions, varying from annular to target shape. Palms and soles are frequently involved, and mucous membranes may be affected. The “target” lesions are pathognomonic for erythema Multiforme.

Question 38

A 10-year-old presents with well-defined, erythematous skin lesions with distinctive, mica-like (silvery) scales that are symmetrical on the knees, elbows, and sacral area, she has ice pick-like pitting of her nails. Additionally, she has thickened nails and onycholysis (separation of the distal nail from the nail bed).

What is the most likely diagnosis?

Answer 38

Psoriasis

Approximately 35% of people with psoriasis experience onset < 20 years of age. Guttate psoriasis is common in children and involves small, scaly papules and plaques of the face, trunk, and extremities. The nail changes are not pathognomonic of psoriasis, but they are commonly seen.