Does severe acne cause an increase in C-Reactive Protein (CRP) levels?

Does Severe Acne Cause an Increased CRP?

Severe acne does not significantly increase systemic C-reactive protein (CRP) levels, even in its severe forms (excluding acne fulminans and acne conglobata). 1

Understanding CRP and Inflammation in Acne

• CRP is an acute-phase protein produced by the liver in response to inflammatory cytokines, particularly IL-6 and TNF-α, and serves as a sensitive marker of inflammation 2
• Normal CRP concentrations are typically below 3 mg/L but can rise above 500 mg/L during acute illness 2
• While acne is an inflammatory skin condition, research indicates that the inflammation it causes remains predominantly localized to the skin and does not significantly elevate systemic inflammatory markers like CRP 1

Evidence on CRP Levels in Acne Patients

• A study specifically examining hypersensitive-CRP (Hs-CRP) levels in patients with moderate and severe acne found no significant difference compared to healthy controls (2.24 ± 4.87 μg/ml vs. 3.12 ± 3.67 μg/ml; P = 0.339) 1
• Additionally, no significant difference in Hs-CRP levels was observed between moderate and severe acne groups (P = 0.165) 1
• This suggests that acne vulgaris, even in severe forms, does not induce significant systemic inflammation as measured by CRP 1

Comparison with Other Inflammatory Skin Conditions

• In contrast to acne, other inflammatory skin conditions like psoriasis and atopic dermatitis do show significant elevations in CRP levels 3, 4
• Patients with moderate-to-severe atopic dermatitis demonstrate significantly increased serum CRP levels compared to controls (0.7±1.0 vs. 0.4±0.7mg/dl; p=0.001) 3
• Similarly, psoriasis patients show elevated CRP levels that correlate with disease severity and decrease with effective treatment 4

Recent Research on Inflammatory Markers in Acne

• A 2023 study investigated the CRP/albumin ratio as a potential inflammatory marker in acne vulgaris and found some differences between acne patients and controls 5
• However, this study examined a ratio rather than absolute CRP levels, and the clinical significance remains unclear 5
• The primary study directly measuring CRP levels in acne patients found no significant systemic elevation 1

Local Inflammatory Mechanisms in Acne

• Propionibacterium acnes (now called Cutibacterium acnes) plays a major role in acne pathogenesis by inducing local inflammatory responses 6
• This bacterium can stimulate the production of corticotropin-releasing hormone (CRH) in the skin, which may modulate local inflammation and sebum production 6
• However, this localized inflammatory response appears insufficient to significantly elevate systemic CRP levels 1

Clinical Implications

• When elevated CRP is found in a patient with acne, clinicians should consider other potential causes rather than attributing it to the acne itself 2
• CRP values >10 mg/L are typically associated with acute infection, inflammatory diseases, solid tumors, or cardiovascular disease rather than common skin conditions like acne 2, 7
• According to CDC/AHA guidelines, if CRP level is ≥10 mg/L, the test should be repeated and the patient examined for sources of infection or inflammation beyond acne 2

Exceptions in Severe Acne Variants

• It's important to note that the research specifically excludes acne fulminans and acne conglobata, which are rare and extremely severe forms of acne 1
• These severe variants may potentially cause systemic inflammation due to their extensive and aggressive inflammatory nature, though specific data on CRP levels in these conditions is limited 1

Monitoring Inflammation in Acne Patients

• For patients with severe acne, monitoring disease activity is better accomplished through clinical assessment rather than CRP measurement 2
• The American Academy of Dermatology guidelines for acne management do not recommend routine CRP testing for monitoring acne severity or treatment response 2
• Laboratory monitoring during acne treatment should focus on parameters relevant to specific therapies (e.g., liver function tests and lipid panels for isotretinoin) rather than inflammatory markers 2