In which tissues does cellulitis commonly occur?
Nov 05, 2025
Source: Cainiu Health
Dr. Liu Wenmin
Introduction
Cellulitis commonly affects tissues such as the skin and subcutaneous tissue, facial soft tissues, lower extremity soft tissues, perianal tissues, and hand soft tissues. The skin and subcutaneous tissue are the most frequent sites of infection. When the skin is compromised (e.g., by abrasions or insect bites), bacteria can easily invade subcutaneous fat, fascia, and other tissues, causing redness, swelling, heat, and pain. The infection may spread through the subcutaneous spaces.
Cellulitis commonly occurs in tissues such as the skin and subcutaneous tissue, facial soft tissues, lower limb soft tissues, perianal tissues, and hand soft tissues. A detailed analysis is as follows:
1. Skin and subcutaneous tissue: This is the most common site of infection. When the skin is damaged (e.g., abrasions, insect bites), bacteria can easily invade subcutaneous fat, fascia, and other tissues, causing redness, swelling, heat, and pain. The infection may spread through subcutaneous spaces, forming extensive inflammatory areas.
2. Facial soft tissues: The facial skin is thin and highly vascularized. If there is skin damage or infections in the oral or nasal cavities, bacteria can rapidly spread to soft tissues such as the cheeks and eyelids, leading to significant local swelling. In severe cases, it may impair eye function or the respiratory tract.
3. Lower limb soft tissues: The lower limbs are prone to trauma and affected by varicose veins, often resulting in poor local blood circulation. Bacteria can thus persist and cause infection, most commonly seen in the lower leg. Symptoms include redness, swelling, and pain in the calf, which may worsen with walking. Some patients may also have fever.
4. Perianal tissues: The perianal area has many skin folds that easily trap dirt and bacteria. Conditions such as anal fissures or hemorrhoids can allow bacteria to invade the surrounding soft tissues, causing redness, swelling, and pain, which intensifies during bowel movements. In severe cases, a perianal abscess may develop.
5. Hand soft tissues: Hands are frequently used and susceptible to cuts or puncture wounds. Bacteria can enter the soft tissues of the palm or fingers through these wounds, resulting in local swelling and pain, impairing hand movement. If the infection spreads, it may involve the finger joints.
When symptoms suggestive of cellulitis appear, prompt medical evaluation is necessary for accurate diagnosis. Appropriate anti-infective treatment should be administered as prescribed, with regular follow-up to monitor resolution of inflammation and prevent further spread of infection.
