Patch tests with killed sonicated microflora in patients with psoriasis

Area of Science:

• Dermatology
• Microbiology
• Immunology

Background:

• Psoriasis is a chronic inflammatory skin condition.
• The role of microbial triggers in psoriasis is under investigation.

Purpose of the Study:

• To investigate the potential role of Malassezia ovalis and Staphylococcus epidermidis in triggering psoriasis.

Main Methods:

• Heat-killed sonicated suspensions of M. ovalis and S. epidermidis were applied to the skin of psoriasis patients and controls.
• Reactions were assessed clinically and histologically.

Main Results:

• All psoriasis patients reacted to M. ovalis, while only 2 controls did.
• Four psoriasis patients reacted to S. epidermidis; no controls did.
• Psoriasis-like lesions developed in reacting psoriasis patients.

Conclusions:

• Malassezia ovalis appears to be a significant trigger for psoriasis in susceptible individuals.
• Further research is warranted to elucidate the mechanisms of M. ovalis in psoriasis pathogenesis.