Sabika says

Columist Sabika Karim considers whether skin tightening treatments cause more harm than good

UNDERSTANDING THE IMPACT OF COLLAGEN-STIMULATING TREATMENTS

With this month’s theme being ‘the face,’ I wanted to explore collagen-stimulating treatments. Recently, viral discussions have raised concerns about non-surgical energy-based treatments, particularly microneedling radiofrequency (RFMN), potentially leading to facial fat loss. In this article, I’ll discuss how we can minimise unwanted side effects by understanding the anatomy of the skin and applying treatments with precision.

THE ROLE OF COLLAGEN IN SKIN HEALTH

As we know, collagen is the primary structural protein in the skin, providing strength and elasticity. With age, collagen production declines, leading to visible signs of ageing such as wrinkles, sagging, and loss of skin firmness. Collagen stimulation is a crucial process in aesthetic medicine, particularly for skin rejuvenation and anti-ageing treatments. Fibroblasts, the primary cells responsible for collagen synthesis, are most abundant in the dermis, particularly in the papillary and reticular layers. These fibroblasts play a vital role in maintaining skin integrity, elasticity, and overall structure by producing collagen and extracellular matrix components.

MECHANISM OF COLLAGEN STIMULATION BY HEAT

Heat-based modalities, such as radiofrequency (RF), ultrasound, and laser treatments, are widely used to stimulate collagen production by inducing controlled thermal injury to the dermis. This process activates fibroblasts and triggers the wound-healing response, leading to the deposition of new collagen fibres.

One key mechanism of heat-induced collagen stimulation is the activation of heat shock proteins (HSPs). When dermal temperatures reach approximately 42–45°C, HSPs, particularly HSP47, are upregulated. These proteins act as molecular chaperones, stabilising newly synthesised collagen and preventing its degradation. The remodelling of collagen occurs over several weeks to months, resulting in improved skin texture, firmness, and elasticity.

PROS AND CONS OF HEATING EPIDERMAL TISSUE

While thermal stimulation of the dermis is beneficial for collagen production, excessive heating of the epidermis can present both advantages and risks.

Pros:

• Moderate epidermal heating can enhance superficial skin tightening and improve texture.

• It may stimulate keratinocyte turnover, leading to brighter, more even-toned skin.

• Increased vascularisation can promote nutrient delivery and overall skin health.

Cons:

• Overheating the epidermis can cause burns, erythema, and post-inflammatory hyperpigmentation (PIH), particularly in darker skin types.

• Excessive thermal damage may lead to epidermal necrosis and scarring.

• Discomfort and downtime increase with higher epidermal temperatures.

To optimise treatment while minimising risks, it is crucial to target the dermis without affecting deeper subcutaneous fat layers. If heat reaches the subcutaneous fat, it may trigger adipocyte death, leading to loss of facial volume. This can make the skin appear lax rather than tightened. However, in areas such as the submentum (under the chin), targeting fat reduction may be desirable.

HOW DEEP SHOULD WE TREAT?

Skin thickness varies by facial region, sex, and age. Women generally have thinner skin than men, and skin thickness decreases with age. A significant reduction occurs in women over 48, with ageing accelerating between 60 and 70 years. 1,2

SUMMARY OF SKIN THICKNESS STUDIES

Two studies measured facial skin thickness using ultrasound and HIFU:

Study 1: Meng et al. (2022)3 This study analysed 118 participants (49 males, 69 females) and measured skin thickness at multiple facial sites:

Study 2: Jeong et al. (2023)4 This study analysed 99 participants (21 males, 78 females) and measured skin thickness at eight facial points:

Key takeaways:

• Average facial skin thickness in these studies (excluding eyelid skin) varied between 1.07mm-1.65mm for females and 1.23mm to 1.877mm for males.

• The extremes of facial skin thickness ranged from 0.63mm to 2.003mm, with most skin thickness being below 2mm.

• Optimal treatment depths for deep dermal treatments will vary between 1mm to 1.6mm for most female patients and 1mm-1.8mm for male patients. Treating at depths of 2mm or more risks reaching the subcutaneous fat layer, potentially causing undesirable fat loss in some areas, but would be advantageous in areas that require a reduction in subcutaneous adiposity such as the submentum.

• It is imperative to respect skin thickness variations and select appropriate treatment depths.

CONCLUSION: SAFE AND EFFECTIVE SKIN TIGHTENING

Energy-based devices are powerful tools for collagen stimulation and proactive anti-ageing when used correctly. Whether utilising HIFU, laser, radiofrequency, or RFMN, we can safely stimulate neocollagenesis while preserving facial volume by targeting the dermis precisely. By respecting skin anatomy and depth, we ensure healthier, firmer, and more youthful skin for our patients.

DR SABIKA KARIM

Dr Sabika Karim, founder of Skin Medical, is a multiaward-winning international educator who combines her NHS GP background with 19 years of aesthetic medical practice to deliver gold standard treatments to her patients at the clinic whilst raising industry standards by teaching and training her peers.

Conflict of Interest Statement – The views expressed are solely my own and have not been influenced or sponsored by any external parties. For full transparency, I am a key opinion leader (KOL) for Sinclair Pharma, Cellese, Evolus, Dermalux, and Erchonia.