Diagnostic spectrum
General information
Dermatophilus congolensis is the causative agent of dermatophilosis, also known as rain scald or rain rot. It is a gram-positive, facultatively anaerobic bacterium of the class Actinomycetia.
Clinically, papules appear first, later pustules and serous exudate, which causes the hair to stick together and creates a tufted, brush-like appearance. Scabs form with underlying exudate. It is easy to pull whole tufts of hair from the affected areas. The lesions are usually not itchy, but often painful.
It is a multifactorial disease: There are more clinical cases during prolonged periods of rain. The excessive moisture leads to a softening of the epidermis and thus causes the skin to become damaged, which is a prerequisite for the bacteria to penetrate. Skin damage caused by injuries or stinging or biting insects is also a predisposing factor.
Transmission usually occurs through direct contact with infected animals, but also indirectly through arthropods and inanimate vectors such as brushes.