Conditions
Cellulitis: skin infections and infected cuts
Cellulitis is a bacterial skin infection that shows up as a red, warm, swollen, tender area, often around a cut, bite or scrape. If it is mild and you have no fever, the doctor evaluates it by video and, if appropriate, prescribes and we send your prescription to your pharmacy. If it is spreading fast or you have fever with chills, go to the ER.
Is it an emergency? Call 911.
Is this an emergency?
This is not an emergency service. Call 911 or go to the nearest emergency room if you have:
- The red area spreads fast or passes the line you drew within a few hours
- Fever with chills, unusual sleepiness or confusion
- Red streaks spreading from the area, or blisters on the infected skin
- Very severe pain in the area
- Infection around the eye or on the face
- A wound that was in the sea and becomes red, swollen and painful
- Any skin infection if you have diabetes or a weakened immune system and you feel unwell
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At a glance
Cellulitis
Common symptoms
- Red skin that keeps spreading
- Skin that is warm to the touch
- Swelling
- Pain or tenderness when touched
- Fever and chills in some cases
- Other names
- Skin infection · Infected cut · Bacterial skin infection
- Treatment
- Antibiotic, only when the medical evaluation calls for it
- Possible complication
- Infection spreading to the blood or deeper tissues
On this page(8)
What is cellulitis?
Cellulitis is a bacterial infection of the deeper layers of the skin. It is usually caused by staph or strep bacteria that get in through a wound, a cut, an insect bite, an animal bite, an ingrown toenail, a tattoo or cracked skin. It is most common on the legs and feet, and it does not spread from person to person.
The risk is higher if you have diabetes, poor circulation, long-term leg swelling, excess weight or a weakened immune system. The cracks from athlete’s foot can also let bacteria in.
In Puerto Rico, watch out for the sea: an open wound that goes into seawater or brackish water (where fresh and salt water mix) can get infected with Vibrio bacteria, which can be serious, especially if you have liver disease, diabetes, cancer or a weakened immune system. If you have a wound, stay out of the sea until it heals, or cover it with a waterproof bandage; if seawater gets in, wash it right away with soap and clean running water.
How we treat cellulitis by video
You see Dr. Diana Nieves Castro, a Puerto Rico–licensed general practice physician with several years of emergency-department experience, in English or Spanish. Show the area on camera in good light, or send photos through the secure link we send you. The doctor asks how it started, whether you have a fever, whether the wound was in the sea, and whether you have diabetes or another condition.
From there she evaluates, diagnoses and treats. If appropriate, the doctor prescribes and we send your prescription to your pharmacy. We never promise an antibiotic before the evaluation: read can telehealth prescribe antibiotics. If a boil or abscess has formed that needs draining, or the infection needs an in-person exam, we tell you and point you to where to go. If you are breastfeeding and the red, warm area is on your breast, see mastitis.
Mark the border: with a pen, draw a line around the edge of the redness and write the date and time. That way you and the doctor can see whether the infection is growing. The doctor tells you when to book a follow-up visit to check it.
Your doctor
Dr. Diana Nieves Castro, MD
General practice physician
Several years of emergency-department experience.
Founding Executive Director of The Health Initiative.
Your visit in 3 steps
Request a visit online 24/7 — we confirm your time by email or text.
Request your visit.
Book a visit and choose "Doctor visit". You pay by card when you request it.
See the doctor by video.
We send you a secure video link. It works on your phone, tablet or computer.
Get your plan.
If appropriate, the doctor prescribes and we send your prescription to your pharmacy, with instructions on what to watch for.
What the visit costs
A skin infection is handled in a US$79 doctor visit, the same price for every age, with no membership. You pay by card when you request the visit, and you get a full refund if the visit can’t take place. It is part of our virtual urgent care. See all prices.
Cellulitis symptoms
Signs of cellulitis start suddenly and can grow quickly in the first 24 hours:
- Red skin that keeps spreading
- Skin that is warm to the touch
- Swelling
- Pain or tenderness when touched
- Fever and chills in some cases
Treatment, and when a lab test is ordered
Cellulitis is treated with antibiotics. A mild infection is usually treated with an antibiotic by mouth, and most people improve in 7 to 10 days; finish the whole course even if you feel better. More serious infections, or infections in people with a weakened immune system, sometimes need IV antibiotics in a hospital. Keeping the leg or arm raised helps bring the swelling down.
If needed, the doctor gives you a lab order, such as a blood count, for a lab near you.
- Wash cuts and scrapes with soap and water and keep them covered until they heal.
- Don’t squeeze or pop a pimple or a bump full of pus.
- If you have diabetes, check your feet every day.
When to go to the ER
For your safety, go to the emergency room or call 911 if you have any of these signs. Don’t wait for a video visit.
- The red area spreads fast or passes the line you drew within a few hours
- Fever with chills, unusual sleepiness or confusion
- Red streaks spreading from the area, or blisters on the infected skin
- Very severe pain in the area
- Infection around the eye or on the face
- A wound that was in the sea and becomes red, swollen and painful
- Any skin infection if you have diabetes or a weakened immune system and you feel unwell
How we care for you
We evaluate, diagnose and treat; if needed, we give you a lab order for a lab near you.
We see adults and children of all ages. Patients under 21: a parent with patria potestad (parental authority) or a legal guardian is on camera for the whole visit and shows photo ID.
Real-time video visit. We send you a secure video link. It works on your phone, tablet or computer.
If appropriate, the doctor prescribes and we send your prescription to your pharmacy. We do not prescribe controlled substances.
You must be physically in Puerto Rico during the visit (visitors, tourists and cruise passengers are welcome).
In an emergency, call 911.
Frequently asked questions
Can cellulitis be treated by video?
Is cellulitis contagious?
Why mark the red border with a pen?
I cut myself at the beach and the cut is turning red. What should I do?
About this page
Author: The Health Initiative
Medical care provided by Dr. Diana Nieves Castro, MD (PR license 24027)
Disclosure: Founding Executive Director of The Health Initiative
Published: 2026-10-02 · Updated: 2026-10-02
Sources (8)
- Cellulitis (MedlinePlus, NIH) (opens in a new tab) (accessed 2026-10-02)
- About Cellulitis (CDC) (opens in a new tab) (accessed 2026-10-02)
- About Vibrio Infection (CDC) (opens in a new tab) (accessed 2026-10-02)
- Preventing Vibrio Infection (CDC) (opens in a new tab) (accessed 2026-10-02)
- About MRSA (CDC) (opens in a new tab) (accessed 2026-10-02)
- Boils (MedlinePlus, NIH) (opens in a new tab) (accessed 2026-10-02)
- Ingrown toenail (MedlinePlus, NIH) (opens in a new tab) (accessed 2026-10-02)
- Breast infection (MedlinePlus, NIH) (opens in a new tab) (accessed 2026-10-02)