A Photo Quiz to Hone Dermatologic Skills

Case 1:
Painful erosions developed on the sole of a 14-year-old girl's foot several weeks earlier. Within the last few days, the condition has spread to the other sole. The patient is otherwise healthy and takes no medications. She enjoys playing soccer and has no history of trauma.

Do you recognize this condition?

A. Tinea pedis.
B. Dyshidrosis.
C. Staphylococcal infection.
D. Streptococcal infection.
E. Candidiasis.

Your treatment plan includes . . .

F. An oral cephalosporin.
G. An imidazole antifungal cream.
H. An allylamine antifungal cream.
I. Mupirocin( cream.
J. A topical corticosteroid cream.

Case 2:
After a basketball game 1 week earlier, a 10-year-old boy was bothered by a blister on his heel. Subsequently, the lesion became sore and red. During the last 2 days, an asymptomatic, rough rash has erupted over most of the child's body. He has a low-grade fever and has been taking ibuprofen( for the pain in his heel.

What are you looking at here?

A. An adverse reaction to the ibuprofen.
B. Urticaria.
C. Scarlatiniform eruption.
D. Infectious mononucleosis.
E. Toxic shock syndrome.

Your initial strategy is to . . .

F. Stop the ibuprofen.
G. Perform a monospot test.
H. Prescribe a systemic corticosteroid.
I. Prescribe an antistreptococcal antibiotic.
J. Prescribe an antistaphylococcal antibiotic.

Case 1: A bacterial culture grew out both Staphylococcus aureus, C, and Streptococcus viridans, D. An oral cephalosporin, F, cleared the infections; mupirocin cream, I, also is effective in this setting. The patient was told to make sure her sneakers are clean.

Tinea pedis usually is pruritic, not erosive. Typically, candidal foot infections do not occur in immunocompetent persons. Dyshidrosis generally manifests as a pruritic, vesicular eruption, not painful erosions.

Case 2: Staphylococcal infections can produce a scarlatiniform eruption, C, as seen in this patient. The absence of pharyngitis ruled out both a streptococcal infection and infectious mononucleosis. Although an adverse reaction to ibuprofen is in the differential, the blister suggested a different cause. Urticaria is generally pruritic and manifests as wheals, not the rough rash seen here. Erythroderma and desquamation of the palms and soles are seen in patients with toxic shock syndrome, who are usually much more severely ill than this patient.

A short course of a first-generation cephalosporin, J, relieved all the symptoms.

Case 3:
A 5-year-old girl with atopic dermatitis is brought to your office with a 4-day history of what the mother describes as "itchy eczema" on her legs.

What are your thoughts about the cause of the rash?

A. Atopic dermatitis flare.
B. Impetigo.
C. Herpes simplex.
D. Molluscum contagiosum.
E. Candidiasis.

Which topical therapy do you offer?

F. A corticosteroid cream.
G. Mupirocin.
H. An imidazole antifungal cream.
I. Salicylic acid( to be applied to each lesion.
J. Acyclovir ointment.

Case 4:
Twenty years after an asymptomatic growth erupted on his shin, a 77-year-old man seeks medical evaluation of the slowly enlarging lesion.

What do you suspect?

A. Seborrheic keratosis.
B. Basal cell carcinoma.
C. Melanoma.
D.Venous angioma.
E. Blue nevus.

Which course of action do you pursue?

F. Perform a shave biopsy.
G. Perform a punch biopsy.
H. Perform an incisional biopsy.
I. Perform an excisional biopsy.
J. Offer reassurance.

Case 3: The sudden onset of this oozing, crusted eruption suggested more than just a flare of eczema. The patient's persistent scratching had caused a secondary staphylococcal infection, impetigo, B. Topical mupirocin, G, resolved the infection.

Herpes simplex occurs in persons with atopy; however, the eruption usually is vesicular and painful. Candidiasis can mimic impetigo, but it is seen much less frequently. Molluscum contagiosum features umbilicated papules.

Case 4: The lesion's pigmentation and general appearance suggested a possible skin cancer. A punch biopsy, G, confirmed the diagnosis of basal cell carcinoma, B. Because of the possibility of melanoma, the biopsy specimen needs to include the base of the tumor; therefore, choices H and I are appropriate as well. A deep shave biopsy, F, may be adequate.

A bluish lesion is not typical of seborrheic keratoses. The appearance of venous angiomas can be deceptive, but they usually look more vascular than this lesion. Blue nevi may be nodular; rarely, they undergo malignant degeneration.

This basal cell carcinoma-the only such lesion on this patient-was surgically removed without complications.

Case 5:
Eight months ago, a short, tapered dose of prednisone( resolved pityriasis rosea in this patient. Now, the 14- year-old boy presents with a similar, mildly pruritic rash on his trunk. He is otherwise healthy, having fully recovered from an upper respiratory tract infection 3 or 4 weeks ago. Ten days ago, he returned from a class camping trip. The patient takes no medication.

Which of the following would you consider . . .

A. A recurrence of the pityriasis rosea.
B. Guttate psoriasis.
C. Tinea corporis.
D. Reaction to an insect bite.
E. Contact dermatitis.

Case 6: A 15-year-old girl seeks treatment of asymptomatic white streaks that appeared on her trunk and thighs a few months earlier. The patient is otherwise healthy, takes no medications, and has not had any significant weight changes in the last year.

What is the likely diagnosis?

A. Tinea versicolor.
B. Pityriasis alba.
C. Vitiligo.
D. Striae.
E. Scars from physical abuse.

Your initial course of action is to . . .

F. Contact the local social services department.
G. Prescribe tretinoin( cream.
H. Prescribe topical corticosteroid cream.
I. Prescribe oral ketoconazole(.
J. Offer reassurance.

Case 5: Pityriasis rosea, A, can occur more than once, and often develops after a recent upper respiratory tract infection. The diagnosis 8 months ago was correct. Guttate psoriasis is usually seen on the legs and does not respond to a tapering course of prednisone. Ringworm in an otherwise healthy person is not as extensive as this patient's eruption. Insect bites and contact dermatitis typically are not flat, scaly patches that are confined to the trunk.

Another course of tapered-dose prednisone resolved the rash. The patient has not had a recurrence for 2 years.

Case 6: Pubertal striae, D, developed as a result of rapid growth. A severalmonth course of tretinoin cream, G, can improve the appearance of these unsightly lesions. Striae usually are found on the back, around the breasts and thighs of adolescent girls and young women, and on the upper arms and back of adolescent boys and men.

Tinea versicolor features discrete hypopigmented or hyperpigmented macules that typically appear on the trunk. Pityriasis alba manifests in persons with atopy as ill-defined, hypopigmented patches. The patches of vitiligo are depigmented. Traumatic injuries generally have a linear or irregular scarring pattern that reflects the source of the injury.