Recall Dermatitis to Metronidazole

Area of Science:

• Dermatology
• Pharmacology
• Immunology

Background:

• Recall dermatitis is an uncommon skin reaction.
• It is associated with patch testing, repeated allergen exposure, and concurrent UV radiation and medication use.
• Etiology of recall dermatitis from primary cutaneous and subsequent oral exposure is unknown.

Observation:

• A case of recall dermatitis is presented.
• The patient experienced a drug eruption secondary to metronidazole.
• Metronidazole was initially used topically for rosacea, then orally for a gastrointestinal infection.

Findings:

• Metronidazole exposure, both topical and oral, can precipitate recall dermatitis.
• This case demonstrates a rare presentation of recall dermatitis.
• The reaction occurred after sequential exposure routes.

Implications:

• Clinicians should be aware of metronidazole's potential to cause recall dermatitis.
• Consider recall dermatitis in patients with a history of metronidazole use presenting with skin eruptions.
• Further research into the etiology of this phenomenon is warranted.