Positive patch test reactions

(A) At a 48-hour reading of abacavir patch test; image is of a patient participating in a large clinical study in which the four patch testing wells contained, in a blinded configuration, (i) abacavir commercial (Ziagen) formulation at 1% in white petrolatum, (ii) abacavir commercial (Ziagen) formulation at 10% in white petrolatum, (iii) petrolatum control, and (iv) Ziagen excipient control.
(B) Close up of 1% and 10% abacavir patch tests formulated in petrolatum in a different patient showing vesicular reaction.