Rain rot, a crusty and scabby skin condition typically affecting livestock, is now being reported as a possible sexually transmitted infection (STI) among men in Europe. The U.S. Centers for Disease Control and Prevention (CDC) has documented nine cases in Barcelona, with additional reports from Lyon, Paris, and Germany. All affected men reported having sex with other men, indicating a disproportionate impact on the gay community.
What Is Rain Rot?
Medically known as dermatophilosis, rain rot is caused by the bacterium Dermatophilus congolensis. Dr. Lawrence Cunningham, a medical expert from UK Care Guide, explains that the condition earned its common name due to its prevalence in tropical regions and its association with damp weather. However, the bacterium can survive in both wet and dry conditions.
Symptoms to Watch For
Symptoms include crusty, scabby patches on the skin that can become uncomfortable. In the European cases, patients experienced an itchy folliculitis-like rash characterized by papules, vesicles, pustules, scabs, nodules, or scaly lesions. While serious complications are rare, secondary bacterial infections can occur if the skin is damaged from scratching. Dr. Cunningham notes that with proper medical attention, the infection rarely reaches deeper tissues.
How Does It Spread?
Typically, humans contract rain rot through direct contact with infected animals (zoonotic infection), making farm workers and veterinarians particularly vulnerable. The bacteria can also survive on contaminated surfaces like grooming tools. However, the recent cases involve no animal exposure, suggesting sexual transmission. Dr. Cunningham points to prolonged skin-to-skin contact during intimate activities as a likely route. All patients had high exposure to STIs, and lesions appeared in areas exposed during sexual contact. Eight patients reported visiting a sauna, where humid conditions favor the bacteria.
Treatment and Risk
The incubation period is one to four weeks, with symptoms often appearing around day six. Diagnosis involves skin samples or bacterial cultures. Treatment includes topical or oral antibiotics, depending on the extent of the infection. Dr. Cunningham emphasizes that dermatophilosis is highly treatable and remains rare, urging the public not to panic. Early medical attention is key to preventing complications.
