The Use of Hyaluronidase in Aesthetic Practice: A Comparative Study of Practitioner Usage in Elective and Emergency Situations.

BACKGROUND: Hyaluronic acids (HAs) continue to be the fillers of choice worldwide and their popularity is growing. Adverse events (AEs) are able to be resolved through the use of hyaluronidase (HYAL). However, routine HYAL use has been at issue due to perceived safety issues. OBJECTIVES: There are currently no guidelines on the use of HYAL in aesthetic practice, leading to variability in storage, preparation, skin testing, and beliefs concerning AEs. This manuscript interrogated the use of this agent in daily practice. METHODS: A 39-question survey concerning HYAL practice was completed by 264 healthcare practitioners: 244 from interrogated databases and 20 from the consensus panel. Answers from those in the database were compared to those of the consensus panel. RESULTS: Compared to the database group, the consensus group was more confident in the preparation of HYAL, kept reconstituted HYAL for longer, and was less likely to skin test for HYAL sensitivity and more likely to treat with HYAL in an emergency, even in those with a wasp or bee sting anaphylactic history. Ninety-two percent of all respondents had never observed an acute reaction to HYAL. Just over 1% of respondents had ever observed anaphylaxis. Five percent of practitioners reported longer-term adverse effects, including 3 respondents who reported loss of deep tissues. Consent before injecting HA for the possible requirement of HYAL was always obtained by 74% of practitioners. CONCLUSIONS: Hyaluronidase would appear to be an essential agent for anyone injecting hyaluronic acid filler. However, there is an absence of evidence-based recommendations with respect to the concentration, dosing, and treatment intervals of HYAL, and these should ideally be available.

Making Sense of Late Tissue Nodules Associated With Hyaluronic Acid Injections.

BACKGROUND: The pathogenesis of delayed-onset tissue nodules (DTNs) due to hyaluronic acid (HA) injections is uncertain. OBJECTIVES: To formulate a rational theory for DTN development and their avoidance and treatment. METHODS: A multidisciplinary and multicountry DTN consensus panel was established, with 20 questions posed and consensus sought. Consensus was set at 75% agreement. RESULTS: Consensus was reached in 16 of 20 questions regarding the pathogenesis of DTNs, forming the basis for a classification and treatment guide. CONCLUSIONS: The group believes that filler, pathogens, and inflammation are all involved in DTNs and that DTNs most likely are infection initiated with a variable immune response. Injected filler may incorporate surface bacteria, either a commensal or a true pathogen, if the skin barrier is altered. The initially high molecular weight HA filler is degraded to low molecular weight HA (LMWHA) at the edge of the filler. Commensals positioned within the filler bolus may be well tolerated until the filler is degraded and the commensal becomes visible to the immune system. LMWHA is particularly inflammatory in the presence of any local bacteria. Commensals may still be tolerated unless the immune system is generally heightened by viremia or vaccination. Systemic pathogenic bacteremia may also interact with the filler peripheral LMWHA, activating Toll-like receptors that induce DTN formation. Given this scenario, attention to practitioner and patient hygiene and early systemic infection treatment deserve attention. Classification and treatment systems were devised by considering each of the 3 factors-filler, inflammation, and infection-separately.

A Consensus on Minimizing the Risk of Hyaluronic Acid Embolic Visual Loss and Suggestions for Immediate Bedside Management.

BACKGROUND: Hyaluronic acid fillers have a satisfactory safety profile. However, adverse reactions do occur, and rarely intravascular injection may lead to blindness. Currently there is no internationally recognized consensus on the prevention or management of blindness from hyaluronic acid filler. OBJECTIVES: The authors sought to give guidance on how to minimize the risk and optimize the management of this rare but catastrophic adverse reaction. METHODS: A multinational group of experts in cosmetic injectables from multiple disciplines convened to review current best practice and develop updated consensus recommendations for prevention and bedside intervention if visual loss occurs after cosmetic injection of hyaluronic acid filler. RESULTS: The consensus group provided specific recommendations focusing on the consenting process, prevention, and early management of visual impairment related to intravascular hyaluronic acid filler injection. CONCLUSIONS: Although visual loss due to filler injections is rare, it is important that both patient and physician be aware of this risk. In this paper the authors describe methods and techniques available to reduce the risk and also document suggested initial management should a clinician find themselves in this situation.

Co-existence of hereditary coproporphyria and porphyria cutanea tarda: The importance of genetic testing.

The porphyrias are a group of inherited disorders that result in defects in the enzymes of the haem biosynthetic pathway, causing photosensitive bullous skin eruptions or abdominal and neurological attacks. Enzymatic defects result in specific porphyrin excretory patterns that are diagnosed biochemically and can be confirmed by genetic testing. Defects in the coproporphyrinogen oxidase (CPOX) enzyme result in the autosomal dominant hereditary coproporphyria. Multiple mutations have been identified in the CPOX gene and incomplete penetrance is noted. Latent carriers without clinical evidence of disease are at risk of life-threatening attacks. Porphyria cutanea tarda may be inherited, but is more commonly acquired. Occasionally two forms of porphyria may co-exist. The importance of genetic testing is discussed.

Molecular and functional analysis of the C-terminal region of human erythroid-specific 5-aminolevulinic synthase associated with X-linked dominant protoporphyria (XLDPP).

Frameshift mutations in the last coding exon of the 5-aminolevulinate synthase (ALAS) 2 gene were described to activate the enzyme causing increased levels of zinc- and metal-free protoporphyrin in patients with X-linked dominant protoporphyria (XLDPP). Only two such so-called gain-of-function mutations have been reported since the description of XLDPP in 2008. In this study of four newly identified XLDPP families, we identified two novel ALAS2 gene mutations, a nonsense p.Q548X and a frameshift c.1651-1677del26bp, along with a known mutation (delAGTG) found in two unrelated families. Of relevance, a de novo somatic and germinal mosaicism was present in a delAGTG family. Such a phenomenon may explain the high proportion of this mutation in XLDPP worldwide. Enhancements of over 3- and 14-fold in the catalytic rate and specificity constant of purified recombinant XLDPP variants in relation to those of wild-type ALAS2 confirmed the gain of function ascribed to these enzymes. The fact that both p.Q548X and c.1651-1677del26bp are located in close proximity and upstream from the two previously described mutations led us to propose the presence of a large gain-of-function domain within the C-terminus of ALAS2. To test this hypothesis, we generated four additional nonsense mutants (p.A539X, p.G544X, p.G576X and p.V583X) surrounding the human XLDPP mutations and defined an ALAS2 gain-of-function domain with a minimal size of 33 amino acids. The identification of this gain-of-function domain provides important information on the enzymatic activity of ALAS2, which was proposed to be constitutively inhibited, either directly or indirectly, through its own C-terminus.

A case of multicentric reticulohistiocytosis responsive to azathioprine in a patient with no underlying malignancy.

Multicentric reticulohistiocytosis (MRH), a rare histiocytic systemic condition characterized by mutilating arthritis and multiple cutaneous nodules, has been associated with malignancy including that of the breast, thyroid and colon. An unsubstantiated link with infectious agents such as mycobacterium tuberculosis has been described. Many treatments have been used with varying success. We describe the case of a 60-year-old man with MRH and no underlying malignancy who initially responded well to azathioprine and whose disease recurred upon cessation. A second course of azathioprine administered in conjunction with antituberculous treatment resulted in disease control. Broader associations and features of this rare disease are discussed.