When to expect infection:
(1) history of infection and/or immunosuppression
(2) progression of skin lesions
(3) change in appearance with weeping, crusts, pustules or vesicles
(4) poor response to therapy for atopic dermatitis
(5) systemic signs (fever, change in behavior, etc)
(6) unexplained leukocytosis
Infectious agents may include:
(1) Staphylococcus aureus
(2) Streptococcus pyogenes (Group A Streptococcous)
(3) Herpes simplex virus (eczema herpeticum)
(4) Herpes zoster
(5) Molluscum contagiosum
(6) HPV (verrucae vulgaris)
(7) Malassezia furfur
Other agents that might be involved include:
(1) dermatophyte
(2) Candida species
The workup may include:
(1) careful clinical evaluation of the lesions
(2) appropriate cultures
(3) smear evaluation
(4) selective biopsy
(5) selective molecular methods
The use of an appropriate therapy should result in clinical improvement if the flare is due to an infection.