[Contact dermatitis to topical antiviral drugs]

Topical antiviral drugs are frequently used. Repeated applications on a skin injured by the viral infection can lead to irritating dermatitis or contact eczema. This secondary effect is often unrecognized because imputed to an increase of the initial dermatosis.

Case 1 - A 58 year-old woman had an eczema around the mouth after the use of Zovirax(R) cream (acyclovir). The patch test with this cream was positive (++ at 96 h) but the detail of all the constituents was negative. Case 2 - A 39 year-old woman had an eczema surrounding the mouth after each use of Zovirax(R) cream and Cuterpes(R) (ibacitabin). The patch tests were doubtful for Zovirax(R) cream, positive for Cuterpes(R) (++ at 96 h) and ibacitabin 1 p. 100 and 10 p. 100 in petrolatum (++ at 96 h). Case 3 - A 58 year-old man had an acute eczema of the face after the use of Zovirax(R) cream and Vira-MP(R) (vidarabin phosphate). The patch tests were positive for the both antiviral topical drugs but negative for each one of their constituents.

Contact dermatitis to antiviral topical drugs are rare, due to active molecule or its excipients. The propyleneglycol, component found in the three antiviral drugs, can induce irritation or allergy. In the most of cases, like in our case number 1 and 3, the patch tests with each constituents of the topical drugs were negative, we conclude to a compound allergy.