Objectives: This lecture aims to provide a comprehensive understanding of pressure alopecias in the context of cosmetic procedures. Specifically, the objectives are to: Describe the two primary types of pressure alopecias: type 1 induced by external pressure and type 2 induced by injectable cosmetic treatments. Explore the underlying pathogenesis, including the role of mechanical trauma, inflammation, and disruption of the hair growth cycle. Discuss the clinical presentation, diagnosis, and differential diagnosis of pressure alopecias, emphasizing the utility of trichoscopy and histopathology.
Introduction: Pressure-induced alopecias (PA) are an uncommon subtype of scarring and non-scarring alopecias that occur after pressure-induced obstruction of capillaries, resulting in hypoxia on the hair bulb that leads to circumscribed areas of hair loss. Recently, PA have been categorized into two primary types: type 1 PA, induced by external pressure, and type 2 PA, involving internal pressure applied to the skin, as in the context of injectable cosmetic treatments. Prompt diagnosis is paramount as it might avoid preventable complications.
Materials / method: To ensure a comprehensive coverage of the topic, a thorough literature search was conducted. Electronic databases, including PubMed, Scopus, and Google Scholar, were utilized to identify relevant articles and studies. The search was performed using appropriate keywords related to pressure-induced alopecias, such as "pressure-induced alopecias," "alopecia induced by external pressure," and "alopecia induced by injectable cosmetic treatments." The search was limited to articles published in the English language to ensure consistency in understanding and interpretation.
Results: Type 2 PA occurs when a substance is injected into the dermis or hypodermis, typically through cosmetic procedures. The primary mechanism believed to cause type 2 PA involves the direct pressure exerted on arterial vessels and capillaries by the injected substances. This pressure occurs in areas with limited flexibility, potentially leading to ischemia and/or vascular tamponade, even without direct blockage of the blood vessels. HA, calcium hydroxyapatite, mesotherapy, and autologous fat grafts have been documented as substances that have been associated with the occurrence of type 2 PA.
Conclusion: This lecture provides a comprehensive overview of pressure-induced alopecias (PA), focusing on type 1 PA induced by external pressure and type 2 PA induced by injectable cosmetic treatments. Type 2 PA is a relatively rare complication often associated with cosmetic injectables. The scalp, forehead, temporal areas, and beard are particularly vulnerable to developing alopecia in these cases. It is crucial for practitioners to be mindful of alopecia as a potential side effect following cosmetic skin infiltrations, with inadequate technique, high-risk areas, and volume being key risk factors.
Disclosures
Did you receive any funding to support your research for this TOPIC?
No
Were you provided with any honoraria, payment or other compensation for your work on this study?
No
Do you have any financial relationship with any entity which may closely compete with the medications, materials or instruments covered by your study?
No
Do you own or have you applied for any patents in conjunction with the instruments, medications or materials discussed in your study?
No
This work was not supported by any direct or non direct funding. It is under the author's own responsability