The SII reflects inflammation in acne vulgaris, but fails to determine categorical severity

Systemic Immune Inflammation Index (SII; calculated by multiplying neutrophil-lymphocyte ratio and platelet count) has been investigated as a marker of inflammation.

we aimed to investigate the relationship of SII with acne severity and whether it can be used as a practical method in determining categorical acne severity.

All participants (aged 15-30 years, n = 212) were prospectively evaluated with acne severity scales, including the Global Acne-Grading System (GAGS), the Comprehensive Acne Severity Scale (CASS), and the Patient-centered Acne Severity Scale. Patients were grouped according to GAGS: healthy individuals (n = 53), patients with mild (n = 44), moderate (n = 86), and severe acne (n = 29). Patients' hemogram data obtained simultaneously with the physical examination were used in the analysis.

The groups were statistically similar in terms of age and gender, both according to acne severity and current lesion types. The neutrophil count was significantly higher in patients with nodulocystic acne than in acne patients with non-inflammatory lesions or healthy individuals (p: 0.022). SII was significantly higher in acne patients with nodulocystic lesions than in individuals with milder lesions, both non-inflammatory and inflammatory (p = 0.004). SII was weakly significantly correlated with GAGS, CASS, and the number of nodulocystic lesions (r = 0.164, p = 0.018; r = 0.147, p = 0.034; r = 0.222, p = 0.001). However, none of the hemogram parameters, including SII, differed in classifying acne severity according to GAGS (p > 0.05).

Systemic immune inflammation index may be a new and reliable inflammatory marker to reflect the severity of inflammation, especially in patients with nodulocystic acne, although it is not useful in categorizing acne severity.