From the Guidelines
The cutaneous layer is approximately 2.0 to 2.5 mm thick, and the subcutaneous layer varies in thickness from a few mm to several centimeters, depending on the anatomic location and individual factors such as age, sex, and body mass index (BMI). The thickness of the cutaneous and subcutaneous layers is a crucial aspect of human anatomy, with significant variations throughout the body and between individuals 1.
Key Factors Influencing Thickness
- Age: The skin is slightly less thick in children, but by puberty, it increases to adult levels 1
- Sex: There are differences in skin thickness between males and females, although these are not fully understood 1
- Body Mass Index (BMI): The subcutaneous layer thickness may vary by BMI, with thicker layers in individuals with higher BMIs 1
- Anatomical Location: The subcutaneous layer is thinnest in the arm and increases in thickness in the thigh, abdomen, and buttocks 1
Clinical Implications
The variation in thickness of the cutaneous and subcutaneous layers has important implications for clinical practices such as insulin injection, with the goal of achieving successful injection into the subcutaneous tissue while minimizing the risk of intramuscular injection 1.
Evidence-Based Recommendations
Based on the most recent and highest-quality evidence, the subcutaneous layer can be successfully injected with a 4-mm pen needle inserted at 90 degrees for most individuals, regardless of BMI or anatomic location 1. This approach takes into account the variability in subcutaneous tissue thickness and aims to optimize insulin absorption while minimizing discomfort and complications.
From the Research
Cutaneous and Subcutaneous Layer Thickness
- The provided studies do not directly address the thickness of the cutaneous and subcutaneous layer 2, 3, 4, 5.
- However, one study discusses the epidermal thickness at different body sites, which may be relevant to understanding the cutaneous layer 6.
- According to this study, the mean thickness of the stratum corneum and cellular epidermis varies by body site, with values ranging from 11.0 to 18.3 microm for the stratum corneum and 56.6 to 81.5 microm for the cellular epidermis 6.
- The subcutaneous layer is not explicitly mentioned in any of the provided studies, and therefore, its thickness cannot be determined based on the available evidence 2, 3, 4, 5, 6.