Med Journal February 2022 | Page 7

Derm Dilemma by Mauri Lester

MD Candidate , Class of 2025 , Oklahoma State University School of Medicine , Tulsa , Ok .
A 21-year-old woman presents with a 10- day history of pruritic , erythematous macules and patches surmounted by yellow , seropurulent crusts in a perioral distribution . Pink papules appeared initially then rapidly evolved into pustules . The eruption began within just a few days of beginning a new summer job at a daycare center . The patient states she enjoys hiking and spends much of her free time outdoors . Medical history is pertinent for atopic dermatitis . The patient denies concomitant cough or fever and any recent travel outside the U . S .
Based on the patient ’ s history and clinical presentation , what is the most appropriate intervention ?
A ) Perform a potassium hydroxide ( KOH ) scraping to confirm the clinical impression of tinea faciei . Initiate a two-week course of a topical azole or allylamine antifungal . Inform patient that in order to reduce the risk of re-infection , household members and pets should be examined and treated if they are found to be the source of infection .
B ) Based on the patient ’ s history and clinical presentation , this is most likely phytodermatitis or plant dermatitis . Reassure patient that this will most likely resolve spontaneously , provided repeat contact with the responsible plant is avoided . To expedite improvement , prescribe a mid-potency topical corticosteroid . Inform patient that this is not contagious , and she can continue working .
C ) The eruption most likely represents impetigo . Instruct the patient to gently cleanse the areas daily with antibacterial soap , and prescribe mupirocin ointment to apply to the nares one-to-two times daily for seven days . An oral antibiotic such as cephalexin may be prescribed . Inform the patient that impetigo is contagious and that she / patient should avoid returning to work until a few days after starting antibiotics .
D ) The patient most likely is experiencing primary herpes simplex infection , and as such , prescribe oral acyclovir or valacyclovir . Educate the patient regarding the recurrent nature of this infection and that subsequent episodes are very likely .
Answer : C . The patient is experiencing an impetigo infection . The lesions begin as papules , which quickly evolve into flaccid vesicles or pustules and , once ruptured , a characteristic yellow or “ honey colored ” crust forms . Children aged 2-5 years are most commonly affected , but impetigo may also be seen in older children and adults as well . The face and extremities are the most common sites of infection . The diagnosis is typically made clinically , but if doubt exists , a bacterial culture may be obtained .
Staphylococcus aureus most commonly causes impetigo , although Beta-hemolytic streptococci may be the responsible pathogen in a minority of cases . A warm and humid climate favor infection . Patients who have impaired skin barrier function are at higher risk of developing bacterial infections such as impetigo . Any skin trauma , including but not limited to wounds , abrasions , burns , dermatitis , scabies , and pre-existing dermatitis , can all be factors that predispose patients to impetigo . Post-infectious sequelae are rare , but glomerulonephritis and rheumatic fever may occur after streptococcal skin infection .
Treatment of impetigo includes topical therapy such as mupirocin or retapamulin if localized , or systemic antibiotics such as cephalexin or dicloxacillin in more extensive or “ deeper ” ( ecthyma ) cases .
175 • The Journal of the Arkansas Medical Society www . ArkMed . org