What Causes Skin Tags?
Skin tags (acrochordons) are benign skin growths primarily caused by mechanical friction in intertriginous areas, with strong associations to metabolic factors including obesity, insulin resistance, and dyslipidemia.
Primary Causative Mechanism
Friction is the direct mechanical cause of skin tag formation. Skin tags develop predominantly in areas where skin rubs against skin or clothing, explaining their typical locations in the neck, axillae, and groin regions 1. A case report documented multiple skin tags arranged in a linear fashion, directly demonstrating friction's etiologic role 1.
Metabolic and Systemic Associations
While friction provides the mechanical stimulus, several metabolic conditions significantly increase susceptibility:
Obesity and Body Mass Index
- Overweight and obese individuals are substantially more likely to develop multiple skin tags 2, 3
- Abdominal obesity and consequent insulin resistance are important contributing factors 2
- The association is particularly strong with multiple skin tags rather than isolated lesions 3
Insulin Resistance and Diabetes Mellitus
- There is a statistically significant relationship between skin tags and diabetes mellitus (p = 0.0073) 4
- Individuals with skin tags have a 1.89 times greater risk of developing diabetes compared to those without skin tags 4
- A significant association exists between the duration of skin tags and the duration of diabetes (p = 0.000) 4
- Skin tags can serve as an early marker of impaired carbohydrate metabolism 4
Dyslipidemia
- Significant associations exist between skin tags and elevated triglycerides, LDL cholesterol, and VLDL cholesterol levels 2
- Hypercholesterolemia shows independent association with skin tags in multivariate analysis 3
- The atherogenic lipid profile appears to be a contributing factor 2
Hormonal Factors
- Elevated leptin levels show significant association with skin tags 2
- A possible trend exists between hypothyroidism and multiple skin tags, though this requires further investigation 3
Associated Dermatologic Condition
Acanthosis nigricans is independently associated with multiple skin tags 3. This association reinforces the connection to insulin resistance, as both conditions share this underlying metabolic abnormality.
Clinical Implications
The presence of multiple skin tags should prompt evaluation for:
- Fasting glucose and HbA1c levels 2, 4
- Complete lipid panel including triglycerides, LDL, and VLDL 2, 3
- Body mass index assessment 2, 3
- Consideration of thyroid function testing 3
Patients with skin tags need suitable interventions including weight reduction, smoking cessation, and dietary modifications 2. The presence of skin tags may facilitate early diagnosis of metabolic syndrome and allow for preventive interventions before more serious complications develop 2, 4.
Important Caveat
Skin tags must be differentiated from other cutaneous lesions such as verruca vulgaris (warts caused by HPV 2 and 4), which have different etiology and treatment implications 5. While skin tags are benign fibroepithelial polyps, warts are infectious lesions requiring different management approaches.