Author: Dr Ian Coulson, Consultant Dermatologist and Editor-in-Chief, 2023.
Edited by the DermNet content department
This 33-year-old man presented in the summer with a streaky rash over his trunk of 2 days duration. In some areas, it is starting to blister. He denies any drug ingestion.
This is typical of a phytophotodermatitis, a rash that results from a phototoxic plant sap coming into contact with the skin, and subsequent light exposure. It results in redness and sometimes blistering of the exposed skin.
He has used a strimmer, or string weeder, and has been working with his top off! The strimmer has spattered phototoxic sap over his trunk. His face was unaffected because he had correctly used a face mask as personal protection.
With photoprotection, the rash will heal, but will leave marked post-inflammatory pigmentation which may last for several months.
