Juvenile Plantar Dermatosis and Contact Dermatitis to Nickel

Case 1:

For several months, a 12-year-old boy has been bothered by intermittent pruritus of the feet. He is very active in sports all year, and his feet tend to perspire heavily. He has a family history of seasonal allergies. He says that the rash worsened after he used an over-the-counter hydrocortisone cream.

What might explain the rash?

A. Contact dermatitis to hydrocortisone.
B. Exacerbation of tinea pedis from hydrocortisone.
C. Contact dermatitis to athletic shoes.
D. Juvenile plantar dermatosis.
E. Impetigo.

(Answer on next page.)

Case 1: This atopic patient has juvenile plantar dermatosis, D, as a result of excessive foot perspiration from his athletic activities. This dermatosis can erupt on the plantar or dorsal surface and is more common in children than adults because the skin surface has not thickened yet. The diagnosis is based on a history of atopy and hyperhidrosis and negative results on a potassium hydroxide evaluation. The patient's condition was exacerbated by contact dermatitis to the hydrocortisone cream, A. Up to 5% of persons who undergo patch testing show contact hypersensitivity to corticosteroids, including hydrocortisone.¹

This patient responded to hygienic measures, such as keeping his feet dry, and a topical corticosteroid to which he was not sensitive.

Tinea pedis can be exacerbated by topical corticosteroids, but tinea is scalier than the condition seen here. Shoe dermatitis is usually confined to the dorsum of the feet and does not extend to the ankles. Impetigo presents with crusting erosions.

Case 2:

A 45-year-old woman has been bothered by a pruritic lesion on her back. For several months, the pruritus has waxed and waned, but the lesion has persisted. She has no rashes elsewhere and has not changed her soap or worn new clothing.

What type of outbreak is this?

A. Contact dermatitis to fabric softener sheets.
B. Contact dermatitis to detergent.
C. Contact dermatitis to nickel.
D. Persistent insect bite reaction.
E. Notalgia paresthetica.

(Answer on next page.)

Case 2: This patient has a contact dermatitis to the nickel in the clasp of her bra, C. The diagnosis was suggested by the patient's report of a rash that erupted on her earswhen she wore gold earrings (which are typically hardened with nickel).

Sensitivity to fabric softener sheets or detergents would produce reactions in areas where the clothing is tightest, such as the waist, or in the axillae, where moisture wicks out the contactant. A persistent insect bite reaction usually produces an erythematous papule, unlike the flat rash seen here. Notalgia paresthetica is a poorly defined pruritic patch that appears asymmetrically on the back and is exacerbated by recurrent rubbing. It has no known cause and is most commonly seen in middle-aged women. Notalgia paresthetica is a diagnosis of exclusion.

Case 3:

One week earlier, a 54-year-old woman had a basal cell carcinoma on her trunk removed by electrodesiccation and curettage. She has been using her usual antibiotic ointment and performing daily wound care. In the past 48 hours, pruritus and vesicles have developed at the wound site. The patient is otherwise healthy.

What does this look like to you?

A. Normal wound healing following electrodesiccation and curettage.
B. Staphylococcal infection.
C. Contact dermatitis to the antibiotic ointment.
D. Methicillin-resistant Staphylococcus aureus.
E. Impetigo from a streptococcal infection.

(Answer on next page.)

Case 3: This patient has a contact dermatitis to the neomycin in the antibiotic ointment, C. Pruritic vesiculation with significant erythema suggests the diagnosis. The eruption resolved after the ointment was discontinued.

The appearance of vesicles 1 week after the patient's procedure would not be considered normal wound healing. Infections generally present with pain rather than pruritus. Impetigo has some pruritus and vesiculation, although more crusting would be expected than is seen in this patient's case because the vesicles of impetigo are more fragile than those of contact dermatitis.

Case 4:

A spreading pruritic rash arose 2 days earlier on the arms of a 44-year-old woman. She is allergic to poison ivy but has not been out in the yard for the past week. Her husband does all the yard work. She has a pet, but it does not go outdoors. She has no exposure history and has not worn any new clothing or perfumes. She has a history of seasonal allergies, but she says that she outgrew them years ago.

What is the likely diagnosis?

A. Contact dermatitis to poison ivy.
B. Psoriasis.
C. Atopic dermatitis.
E.D.Pityrosporum folliculitis.
Photodermatitis to sunscreen.

(Answer on next page.)

Case 4: The patient has contact dermatitis to poison ivy, A. She came into contact with the allergens when she picked up the clothes that her husband had worn while doing yard work.

Psoriasis generally has a more gradual onset. Guttate psoriasis appears suddenly but is more widespread than this patient's rash. Atopic dermatitis has a follicular variant, but this patient had no history of such rashes. Even if she did have such a history, there was no precipitating factor in this instance. Pityrosporum folliculitis is typically confined to the trunk. Photodermatitis to sunscreen is unlikely because this patient's rash is not photodistributed; moreover, a rash caused by photodermatitis would not be as papular as one resulting from poison ivy exposure.

References:

REFERENCE:

1.

Bircher AJ, Thurlimann W, Hunziker T, et al. Contact hypersensitivity to corticosteroids in routine patch test patients. A multi-centre study of the Swiss Contact Dermatitis Research Group.

Dermatology.

1995;191:109-114.