Cellulitis and Abscess
The redness may lag behind the infection
General information from an emergency physician. It adds to your discharge papers and does not replace them or your own doctor. What this site is and isn’t
Key Takeaways:
- Cellulitis is an infection in deeper skin. An abscess is a pocket of pus, and drainage is its main treatment.
- Redness may spread briefly after treatment starts. Marking its edge helps track the trend over 48 to 72 hours.
- Return now for severe pain beyond what the skin looks like. Darkening skin, blisters, or rapid worsening also need immediate return.
About Your Diagnosis and ED Workup
Bacteria can enter through a crack, cut, ulcer, or wound. Fungal infection between the toes can also let them in. The body’s response causes redness, warmth, swelling, and pain.
An abscess is a walled-off pocket of pus. A hand examination can miss a deep pocket. Ultrasound can help when it is unclear whether fluid needs drainage.
Red, swollen skin is not always infection. Vein problems or a blood clot can look similar. So can lymphedema, contact dermatitis, and gout. Redness in both lower legs is rarely cellulitis unless there was skin injury. If treatment does not work as expected, the diagnosis may need another look.
A low LRINEC blood-test score cannot exclude necrotizing fasciitis. This is a rare, fast-moving infection. Symptoms and clinical judgment matter more than the score. The score is not for self-diagnosis.
First Steps and Evidence-Based Home Care
1. Follow the treatment plan you were given
Cellulitis is treated with antibiotics. A drained abscess may or may not need one. The choice depends on the infection and the patient’s risks. Do not add, stop, or change a drug based on this page.
2. Mark the edge and check the direction
Draw around the outer border of redness if your discharge plan allows it. Early redness can move past the line for a day or two. Dying bacteria can briefly increase inflammation. By about 72 hours, redness should be improving. No improvement or worsening by 48 hours needs reassessment.
3. Care for skin breaks that allow infection in
For leg cellulitis, cracks and fungal infection between the toes can be a doorway for bacteria. Ask how to treat that skin problem and reduce recurrence.
4. Do not rely on heat or ice as treatment
Warm compresses may help an abscess localize, but they do not replace drainage. Ice is not a standard cellulitis treatment.
Timeline and Expected Recovery Course
The skin may look slightly worse during the first day or two. This can happen even when the antibiotic is killing the bacteria. Redness reflects inflammation. It is not a visible line of live germs.
Redness should improve by about 30% at 72 hours. Swelling and warmth can last to day 10 without proving treatment failure. Bacteria clear faster than the tissue heals. Fluid must still drain through lymph vessels affected by inflammation.
No improvement or worsening by 48 hours needs another evaluation. A resistant germ or a different diagnosis may be responsible. Cellulitis can recur, especially with lymphedema, vein problems, fungal foot infection, or prior episodes.
Emergency Red Flags: Return Immediately
Return to the emergency department for any of these:
- New or worsening pain, swelling, redness, or warmth after the initial improvement window.
- Fever, chills, or new whole-body symptoms.
- A red streak spreading away from the area.
- Pain far worse than the skin looks, tense swelling, dark or dying skin, or blisters, because a rapidly destructive infection must be reconsidered.
- No improvement, or worsening, by 48 hours.
- With infection near an eye: new eye-movement pain, vision trouble, a bulging eye, or severe swelling, because infection behind the eye requires prompt imaging and treatment.
This list does not cover everything. If the area changes rapidly or the person becomes very ill, return to the emergency department.
Reviewed September 3, 2026