Intertrigo and Tinea Cruris

April 2, 2006

A persistent, 2-month-old rash under both breasts has not responded to overthe-counter antifungal creams. The 55-year-old patient now seeks medical care;she is otherwise healthy.

Case 1:

A persistent, 2-month-old rash under both breasts has not responded to over the-counter antifungal creams. The 55-year-old patient now seeks medical care;she is otherwise healthy.Do you recognize this eruption?

A.

Intertrigo.

B.

Tinea cruris.

C.

Erythrasma.

D.

Candidiasis.

E.

Contact dermatitis.
Your treatment plan includes . . .

F.

An imidazole antifungal cream.

G.

An allylamine antifungal cream.

H.

A clindamycin lotion.

I.

A corticosteroid cream.

J.

A desiccating agent, such as aluminum chloride solution.

Case 2:

A 33-year-old man with a history of psoriasis is botheredby a persistent, pruritic rash that developed in thegroin area. This eruption, which is superimposed on thepsoriasis, has not responded to the topical corticosteroidbeing used for the underlying disease. The patient hasnot tried a new detergent or worn recently purchasedclothes.What is the likely cause of this outbreak?

A.

A psoriasis flare.

B.

A seborrhea flare.

C.

Tinea cruris.

D.

Candidiasis.

E.

Contact dermatitis to psoriasis medications.
Your treatment plan includes . . .

F.

An oral antihistamine.

G.

An imidazole antifungal cream.

H.

An allylamine antifungal cream.

I.

A more potent corticosteroid cream.

J.

A systemic corticosteroid.

Case 1:

A potassium hydroxide examination ruled out a fungal cause, the rashdid not respond to topical antibiotics, and there was no history of exposure tosupport contact dermatitis; therefore, the diagnosis by exclusion was intertrigo,

A.

A desiccating agent,

J,

can help prevent this intertriginous dermatitis, whichis caused by skin rubbing against skin in a moist, warm site.

Case 2:

Psoriasis increases the riskof dermatophyte infection; therefore,a potassium hydroxide (KOH) examinationneeds to be performed inthis setting. The KOH evaluationconfirmed

tinea cruris

,

C

, which respondsto either an imidazole,

G

, oran allylamine,

H

, antifungal cream.Had the KOH preparation beennegative, more aggressive treatmentwould have been necessary: for example,a short-term increase in thepotency of the patient's topical corticosteroidfor a flare of psoriasisor seborrhea, or an antifungal forseborrhea.

Case 3:

For 2 days, a 6-year-old girl with a family history of seasonal allergies has hada pruritic rash that recurs at different sites on her body. The child recentlycompleted a course of amoxicillin for an upper respiratory tract infection. Noone else in her household complains of itching. The family has a pet dog.Which of the following are relevant to the diagnosis?

A.

The history of an upper respiratory tract illness.

B.

The household pet.

C.

The transient nature of the rash.

D.

The family history of allergies.

E.

The absence of pruritus in other family members.
Your initial approach is to . . .

F.

Prescribe a topical corticosteroid.

G.

Prescribe an oral antihistamine.

H.

Prescribe a systemic corticosteroid.

I.

Initiate scabies therapy for the entire family.

J.

Recommend that the dog be removed from the home.

Case 4:

Two days earlier, an asymptomatic, flat rash developed on the face of a5-year-old boy who had had a low-grade fever and malaise. He was taking penicillinfor a suspected--but unconfirmed--streptococcal infection.Your differential includes . . .

A.

Urticaria.

B.

Contact dermatitis.

C.

Scabies.

D.

Viral exanthem.

E.

Adverse reaction to penicillin.
Your management strategy includes which of the following?

F.

Prescribe an oral antihistamine.

G.

Prescribe a systemic corticosteroid.

H.

Change the antibiotic to erythromycin.

I.

Discontinue the penicillin and withhold all antibiotic therapy.

J.

Treat the entire family for scabies.

Case 3:

The clinical presentation and history point to

urticaria

, an eruption oftransient, ,

C

, pruritic wheals that often follows an upper respiratory tract illness,

A

, and may be exacerbated by penicillin. An oral antihistamine,

G

, amelioratedthe patient's symptoms. The family history of atopy and the presenceof the dog were irrelevant.

Case 4:

Fifth disease is one of many

viral exanthems

,

D

, that affect children.The condition produces a transient, blanching, erythematous eruption that isusually asymptomatic. Urticaria, contact dermatitis, and scabies typically featureraised, pruritic lesions.This patient's parents were told to discontinue the antibiotic,

I

; the child'srash resolved uneventfully.

Case 5:

A 45-year-old woman presents forevaluation of an asymptomatic, lacyrash on her arms, legs, and thighs ofa few days' duration. She is takingan antimalarial agent for lupus erythematosus,which is currently inremission. The patient is concernedthat the rash is associated with thedisease or the medication.What are your thoughts aboutthe cause of the rash?

A.

Vasculitis.

B.

An adverse drug reaction.

C.

Livedo reticularis.

D.

Contact dermatitis.

E.

Cellulitis.
Your initial approach includeswhich of the following?

F.

Order a complete blood analysis.

G.

Perform a skin biopsy.

H.

Discontinue the antimalarialmedication.

I.

Prescribe a cephalosporinantibiotic.

J.

Prescribe a systemiccorticosteroid.

K.

Reevaluate the patient toassess the status of her lupuserythematosus.

Case 5:

The clinical diagnosis was

livedo reticularis

,

C

, an inflammatorycondition of the dermal vessels that iscommonly seen in patients with connectivetissue diseases. It typicallymanifests as a lacy, or netlike, macularerythema on the extremities. Notreatment is necessary; however, a reassessmentof the activity of the underlyingdisease is warranted,

K

.Vasculitis is usually painful andpresents as petechiae or purpura.Generally, contact dermatitis is pruritic,as are adverse drug reactions,which are also more widespread.Pain and more localized involvementcharacterize cellulitis.

Case 6:

A 48-year-old man presents with a pruritic, tender rash in the groin area.Since the rash erupted 4 weeks earlier, the patient has tried over-the-counterhydrocortisone creams, antifungal creams, and neomycin ointment. None ofthese remedies provided any relief.What is the likely cause of the eruption?

A.

Intertrigo.

B.

Tinea cruris.

C.

Erythrasma.

D.

Candidiasis.

E.

Contact dermatitis.
Which treatment do you offer the patient?

F.

An imidazole antifungal cream.

G.

An allylamine antifungal cream.

H.

A topical clindamycin lotion.

I.

A topical corticosteroid cream.

J.

A desiccating agent, such as an aluminum chloride solution.

Case 6:

The diagnosis of

erythrasma,

C

, typically is made when the rashdoes not respond to antifungal therapy.A potassium hydroxide examinationcan rule out a dermatophyte infection.Erythrasma was confirmedby the rash's characteristic coral-redfluorescence when seen under aWood lamp. Erythrasma is a bacterialinfection that responds to topicalclindamycin,

H

, or erythromycin.The use of a desiccant,

J

, may helpprevent reinfection.The Wood lamp examinationeliminated intertrigo from the differential.Contact dermatitis usually ispruritic and nontender. This patientdid not have the satellite lesions thatare typical of candidiasis.