Hyaluronidase for Dermal Filler Complications: Review of Applications and Dosage Recommendations

BACKGROUND

Hyaluronidase (Hyal) can reverse complications of hyaluronic acid (HA) fillers, which has contributed substantially to the popularity of such procedures. Still, there are differing opinions regarding Hyal treatment, including dosage recommendations in filler complication management.

OBJECTIVE

We aimed to address unanswered questions regarding Hyal treatment for HA filler complications, including timing and dosage, skin pretesting, properties of various Hyals and interactions with HA gels, and pitfalls of the treatment.

METHODS

PubMed and Google Scholar databases were searched from inception for articles on Hyal therapy for filler complications. Articles were evaluated regarding their contribution to the field. The extensive literature review includes international leaders' suggestions and expert panels' recommendations.

RESULTS

There are limited controlled data but increasing clinical experience with Hyal treatment. The currently used Hyals provide good results and have an acceptable safety profile. Nonemergent complications such as the Tyndall effect, noninflamed nodules, and allergic or hypersensitivity reactions should be treated with low or moderate Hyal doses. Hyal should be considered with prior or simultaneous oral antibiotic treatment in managing inflammatory nodules. Hyal may be tried for granulomas that have not responded to intralesional steroids. Emergent complications such as vascular occlusion and blindness require immediate, high-dose Hyal treatment. Regarding blindness, the injection technique, retrobulbar versus supraorbital, remains controversial. Ultrasound guidance can increase the efficacy of the above interventions.

CONCLUSIONS

Hyal is essential in aesthetic practice because it can safely treat most HA filler complications. Immediate Hyal treatment is required for emergent complications. Aesthetic practitioners should be versed in using Hyal and effective dosage protocols.

Reduced virulence of melanized Cryptococcus neoformans in Galleria mellonella

Fungal melanins are important in the virulence of many pathogenic fungi. In this study, we examined the role of melanin in the interaction between Cryptococcus neoformans and the invertebrate host, Galleria mellonella. C. neoformans was able to melanize in the presence of G. mellonella homogenate, indicating the presence of melanin substrates. Melanization was confirmed by the recovery of acid-resistant particles that were recognized by anti-melanin antibodies. In addition, we tested the effect of fungal melanization on virulence. Surprisingly, G. mellonella larvae infected with melanized fungal cells lived longer than those infected with non-melanized fungi. When the cellular immune response of G. mellonella to melanized and non-melanized cells was compared, inflammatory nodules were observed in both groups. However the response was stronger in larvae infected with melanized cells. These results suggest that fungal melanin activates the immune response of G. mellonella, thereby resulting in the decreased virulence observed with melanized cells.