2025 – PAGE 157 – DERMATOLOGY
STAPHYLOCOCCUS EPIDERMIDIS
Staphylococcus epidermis is the most likely answer if you are presented with a premature baby that has a skin infection.
CELLULITIS
Cellulitis is defined as a well-demarcated area of erythema, edema, and induration secondary to an infection. It may be associated with bullae. For treatment, start with a 1st generation cephalosporin such as Cefazolin or Cephalexin as your first line agent.
TINEA CORPORIS
In tinea corporis, a thin, circular lesion with a RAISED border, CENTRAL CLEARING and a LEADING EDGE (scale at the leading/expanding border) is noted. The ring of the “ringworm” looks like a worm. Treat with antifungal creams such as clotrimazole, ketoconazole, terbinafine, or luliconazole.
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PEARL: Although tinea corporis and granuloma annulare can have a similar appearance, remember that granuloma anuulare has no scale, whereas tinea corporis has lots of scale.
TINEA VERSICOLOR (AKA PITYRIASIS VERSICOLOR)
Tinea versicolor results in hypopigmented OR hyperpigmented macules. It’s caused by MALASSEZIA FURFUR. Lesions may fluoresce under Woods lamp. Treat with topical selenium sulfide lotion/shampoo (1-2.5%) or zinc pyrithione 1% shampoo. Second line treatment includes oral itraconazole or fluconazole, but NOT oral griseofulvin (use that for T. capitis).
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PITYRIASIS ROSEA
Pityriasis rosea presents as oval, parallel lesions with THICK scales. Look for a herald patch (first lesion). It is associated with winter and spring. Lesions are often in a “Christmas tree pattern.” Treat with light exposure.
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PEARL: Unlike secondary syphilis, there are no lesions on the palms/soles.
MOLLUSCUM CONTAGIOSUM
Molluscum contagiosum results in flesh-colored, pearly papules that are dome-shaped and umbilicated. It is caused by the POX virus. NO treatment is needed, but sometimes you may use cryotherapy or topical cantharidin, podophyllotoxin, imiquimod, or potassium hydroxide.
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