From the Research
Beta-defensin is the antimicrobial agent that prevents dermatophyte infection in patients with psoriasis. The role of beta-defensins in preventing dermatophyte infections in patients with psoriasis is supported by several studies, including one published in 2009 1, which found that human beta-defensin-2 (hBD-2) is strongly expressed in lesional psoriatic epidermis and reaches biologically relevant concentrations in lesional skin. This increased expression of beta-defensins helps explain why patients with psoriasis have a lower incidence of cutaneous infections, including those caused by dermatophytes (fungi that cause conditions like athlete's foot, ringworm, and nail fungal infections). The mechanism involves beta-defensins directly killing or inhibiting the growth of dermatophytes by disrupting their cell membranes. Additionally, beta-defensins can modulate the immune response, recruiting immune cells to the site of potential infection. This enhanced antimicrobial defense is part of the complex immunological changes seen in psoriatic skin, where inflammation triggers increased production of these protective peptides. While this provides some protection against dermatophytes, it's essential to note that standard antifungal treatments should still be used if a dermatophyte infection does occur in a patient with psoriasis, as supported by a recent study in 2024 2. Some studies have also investigated the use of antifungal combination therapy in treating recalcitrant dermatophytosis, with one study published in 2023 3 finding that the combination of terbinafine and itraconazole had a higher clinical and mycological cure rate when compared to the use of either drug alone as monotherapy. However, the most recent and highest quality study on this topic is the one published in 2024 2, which confirms that human circulating beta-defensin-2 levels associate with psoriasis and attenuate upon biologic interventions. Therefore, beta-defensin is the key antimicrobial agent that prevents dermatophyte infection in patients with psoriasis, and its role is supported by the most recent and highest quality evidence. Key points to consider include:
- Beta-defensins are antimicrobial peptides that play a role in preventing dermatophyte infections in patients with psoriasis.
- The increased expression of beta-defensins in psoriatic skin helps explain the lower incidence of cutaneous infections in these patients.
- Beta-defensins can modulate the immune response and recruit immune cells to the site of potential infection.
- Standard antifungal treatments should still be used if a dermatophyte infection does occur in a patient with psoriasis.
- The combination of terbinafine and itraconazole may be an effective therapeutic strategy in the management of dermatophytosis, but more research is needed to confirm this.