Seborrheic dermatitis is characterized by intermittent, active phases that manifest with burning, scaling, excess oil secretion, and itching. Seborrheic dermatitis usually appears over areas that are rich in sebaceous glands, such as the lateral sides of the nose and the nasolabial folds, eyebrows, glabella, and scalp.9
The exam holds the key to diagnosis
The diagnosis of erysipelas is based on clinical manifestations. Blood cultures, needle aspirations, and punch biopsies are not usually helpful. Blood cultures are positive in less than 5% of cases.4 Punch biopsy is positive in 20% to 30% of cases.4
Needle aspiration and skin biopsies may be considered for a patient with a severe infection that is not responding to treatment, or for a patient who has diabetes, a malignancy, or unusual predisposing associated factors, such as an immersion injury, an animal bite, neutropenia, or immunodeficiency.
Treatment centers on penicillin
With early diagnosis and proper treatment, the prognosis for erysipelas is excellent. Empiric antimicrobial therapy should include activity against beta-hemolytic Streptococcus. Penicillin is the treatment of choice4,10 (strength of recommendation [SOR]: A). Streptococcus strains are susceptible to penicillin and 99.5% are susceptible to clindamycin. A 7% macrolide resistance has been reported in the United States.4
Oral therapy is recommended for mild infections (or for those who have improved after intravenous [IV] antibiotics). Treat with penicillin V 500 mg PO 4 times daily or amoxicillin 500 mg PO 3 times daily. Other choices include clindamycin 300 mg PO for 7 to 10 days; azithromycin 500 mg PO for 1 day, followed by 250 mg PO daily for 4 days; or clarithromycin 250 mg PO twice a day for 7 to 10 days4,10 (SOR: A).
Consider hospitalization for severely ill patients, for those who are unable to tolerate oral medications, and for those who require parenteral antibiotic therapy for systemic symptoms and rapidly progressing erythema4 (SOR: A). Regimens include penicillin G 2 million to 4 million units IV every 4 to 6 hours; cefazolin 0.5 to 1 g IV every 8 hours; cefotaxime 1 to 2 g IV every 8 hours; and ceftriaxone 1 to 2 g IV every 24 hours.
If staphylococcal infection is suspected, a penicillinase-resistant semisynthetic penicillin or a first-generation cephalosporin, such as cefazolin, can be selected. For oral therapy, cephalexin 500 mg 4 times daily can be used4,11 (SOR: A). Macrolides (erythromycin 250 mg PO every 6 hours) are also an option4 (SOR: A). For presumed methicillin-resistant Staphylococcus aureus (MRSA), you can prescribe clindamycin 600 mg IV every 8 hours; vancomycin 15 mg/kg IV every 12 hours; or linezolid 600 mg every 12 hours. The total duration of antibiotic therapy may be extended to up to 14 days, and tailored to clinical improvement.4,10