Diagnosis: Fixed drug reaction
Description: Dark patches on the skin
Morphology: Hyperpigmentation
Site: Back
Sex: M
Age: 64
Type: Clinical
Submitted By: Ian McColl
Differential DiagnosisHistory:
These hyperpigmented patches were due to a non steroidal anti inflammatory drug taken for intermittent gout. Fixed drug reactions cause hyperpigmentation like this because of damage to the basement membrane causing melanin to be taken up by melanophages in the dermis.