Flagellate Dermatitis by Shiitake Mushroom

Area of Science:

• Dermatology
• Toxicology
• Gastroenterology

Background:

• Shiitake mushrooms (Lentinula edodes) are increasingly popular globally for culinary use.
• Mushroom consumption can occasionally lead to adverse dermatological reactions.
• Flagellate dermatitis is a distinctive skin eruption characterized by a whip-like pattern.

Observation:

• A previously healthy young male developed flagellate dermatitis after consuming raw or undercooked shiitake mushrooms.
• The patient presented with pruritic, erythematous, and linear lesions consistent with flagellate dermatitis.
• No systemic symptoms or other complications were noted.

Findings:

• The skin condition was attributed to a potential toxic or immunologic reaction to shiitake mushrooms.
• Treatment with topical dexamethasone 0.1% cream resulted in complete remission of symptoms within 7 days.
• The reaction was self-limited, resolving without sequelae.

Implications:

• This case highlights shiitake mushroom-induced flagellate dermatitis as a potential cause of acute skin reactions.
• Increased global consumption of shiitake mushrooms may lead to a rise in reported cases, including in Western countries.
• Dermatologists should consider shiitake mushroom ingestion in the differential diagnosis of flagellate dermatitis.