Arrange the pathophysiologic events of acne in the correct sequence.

Arrange the pathophysiologic events of acne in the correct sequence.

• A. Excessive sebum production → Alterations in follicular growth and differentiation → Colonization by Propionibacterium acnes → Immune response and inflammation
• B. Colonization by Propionibacterium acnes → Excessive sebum production → Immune response and inflammation → Alterations in follicular growth
• C. Alterations in follicular growth and differentiation → Excessive sebum production → Colonization by Propionibacterium acnes → Immune response and inflammation
• D. Immune response and inflammation → Excessive sebum production → Colonization by Propionibacterium acnes → Alterations in follicular growth

Answer: (A)

Acne begins with hormonal signals that drive the sebaceous glands to produce more sebum. The excess sebum, together with abnormal keratinocyte turnover in the hair follicle, leads to plugging of the pore (follicular growth and differentiation changes). This blocked follicle creates an anaerobic environment that favors colonization by Propionibacterium acnes (Cutibacterium acnes). The presence of the bacteria and its lipid byproducts then triggers an innate immune response, with inflammatory mediators drawing in inflammatory cells and producing the characteristic red, swollen lesions. So the sequence—more sebum production, followed by follicular plugging, then bacterial colonization, then inflammation—matches how acne typically develops.

Acne begins with hormonal signals that drive the sebaceous glands to produce more sebum. The excess sebum, together with abnormal keratinocyte turnover in the hair follicle, leads to plugging of the pore (follicular growth and differentiation changes). This blocked follicle creates an anaerobic environment that favors colonization by Propionibacterium acnes (Cutibacterium acnes). The presence of the bacteria and its lipid byproducts then triggers an innate immune response, with inflammatory mediators drawing in inflammatory cells and producing the characteristic red, swollen lesions.

So the sequence—more sebum production, followed by follicular plugging, then bacterial colonization, then inflammation—matches how acne typically develops.