Doxycycline is commonly prescribed  due to its anti-inflammatory and antibacterial properties. It helps reduce painful nodules, swelling, and secondary infection by inhibiting bacterial protein synthesis and dampening inflammatory cytokines. It is typically used for moderate HS or as part of combination therapy with topical agents. Treatment often lasts several weeks to months, depending on response. Common side effects include photosensitivity, gastrointestinal upset, and esophageal irritation, so patients should take it with water and avoid excessive sun exposure.