Photocontact urticaria from chlorpromazine

Area of Science:

• Dermatology
• Photodermatology
• Clinical Medicine

Background:

• Chlorpromazine is a phenothiazine antipsychotic medication.
• Photosensitive eczema is a known adverse reaction to certain drugs.
• Delayed onset of photosensitivity can complicate diagnosis.

Observation:

• A patient presented with clinical features characteristic of drug-induced photosensitive eczema.
• The patient's reaction was linked to chlorpromazine use.
• Specific diagnostic testing was performed.

Findings:

• The patient exhibited typical delayed photosensitive eczema symptoms.
• Photopatch testing confirmed chlorpromazine as the causative agent.
• Urticarial lesions were also observed upon photopatch testing.

Implications:

• This case reinforces chlorpromazine's role in photosensitive eczema.
• Photopatch testing is crucial for identifying drug-induced photosensitivity.
• Awareness of this adverse effect is important for clinicians managing patients on chlorpromazine.