What does cellulitis mean?
Cellulitis is a common but potentially serious bacterial infection of the skin and the underlying soft tissue. It typically develops when bacteria such as Streptococcus or Staphylococcus enter through a cut, crack, ulcer, or insect bite, producing an area of skin that becomes red, hot, swollen, and painful, most often on the lower legs. The condition spreads quickly if untreated and may be accompanied by fever and chills; severe cases can lead to bloodstream infection, so prompt treatment with antibiotics is essential. The term appears frequently in medical writing and health reporting, and it also surfaces in compound forms naming specific sites of infection, such as orbital or periorbital cellulitis around the eye. Although its name resembles the unrelated cosmetic term 'cellulite', cellulitis carries none of that sense — it refers strictly to infection and inflammation, making awareness of the distinction genuinely useful for readers encountering either word in print or conversation.
nounA bacterial infection of the skin and the tissues beneath it, typically causing redness, swelling, warmth, and pain, most often affecting the lower legs. It occurs when bacteria, usually streptococci or staphylococci, enter through a break in the skin.
- A common bacterial infection of the dermis and subcutaneous tissue, marked by redness, warmth, swelling, and tenderness, usually caused by Streptococcus or Staphylococcus bacteria entering through broken skin.
"What began as a small insect bite developed into cellulitis that required a course of intravenous antibiotics."
"The patient was admitted to hospital after antibiotics failed to clear the cellulitis in her left calf."
"Doctors warned that untreated cellulitis can spread rapidly to the bloodstream."
The classical plural 'cellulitides' exists in specialist pathology writing, particularly when referring to multiple distinct types or sites of the condition, but 'cases of cellulitis' is far more common in general usage.
"The journal reviewed several recurrent cellulitides observed in immunocompromised patients."
Despite its name suggesting something cosmetic, cellulitis is a serious skin infection — the word shares its root with 'cellulite', but the two conditions could hardly be more different.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of cellulitis
Cellulitis derives from the Latin cellula, meaning 'small chamber' or 'little cell', itself a diminutive of cella ('store-room'), combined with the Greek-derived suffix -itis denoting inflammation. The term was coined in medical Latin to describe inflammation of cellular (connective) tissue, and it entered English usage in the early nineteenth century as pathology became systematised. It shares this Latin root with words such as cellular, cellulose, and cellulite, which all reference small cells or compartments rather than any connection to infection itself.
How cellulitis is actually used
Cellulitis is a formal medical term, standard in both clinical and everyday health contexts. In British English it is sometimes pronounced with stress on the first syllable, but /ˌsɛljuˈlaɪtɪs/ is widely accepted in both varieties. The plural form is rarely used outside pathological literature describing multiple episodes or sites of infection.
Easily confused with cellulitis
Cellulite is the harmless dimpled appearance of fat under the skin, while cellulitis is an active bacterial skin infection requiring medical treatment.
Erysipelas is a more superficial bacterial skin infection with sharply raised, well-defined borders, whereas cellulitis involves deeper tissue with less distinct margins.