Are you having back pain with any of the following?

  • Severe pain, weakness or tingling in your leg(s).
  • Difficulty stopping urination or loss of control of bladder or bowels.
  • Unexplained fever, nausea or vomiting.
  • A history of cancer or unexplained weight loss.

We understand that you are experiencing one or more of the health issues that might be impacting your back pain.

We recommend that you discuss these health issues with your doctor before proceeding with this program.

Once you are cleared by your doctor to do this program, we hope it helps you find relief from your back pain.

Provider photo for Jonathan Volk

Jonathan Volk, MD

Infectious Diseases

Welcome to My Doctor Online, a web site that my colleagues and I developed to make it easier for you to take care of your healthcare needs. On this site you will find answers to many of your questions about my clinical practice. Also included are several online features that will allow you to e-mail me, check your laboratory results and refill prescriptions. I hope you find its content informative and useful.

My Offices

San Francisco Medical Center
Appt/Advice: 415-833-2200

See all office information »

subContentURL_nobackslash = resources/dc/condition

firstActiveTabUrlFragment = resources/dc/conditionlist

subContentURL_nobackslash = resources/dc/condition

JSP2Include = /mdo/presentation/conditions/condition.jsp?nocache=true


Most of the time, your skin prevents bacteria from entering your body. Cellulitis is a common infection that can occur when bacteria enters your body through a cut or scratch on your skin. The infected skin can become red, painful, tender, or swollen.

Mild cellulitis goes away on its own or can be treated with antibiotics. You are more likely to get cellulitis if you are recovering from surgery or have another health problem, such as:

  • Obesity
  • Diabetes
  • Chronic swelling in your arms or legs
  • A weakened immune system

Cellulitis can become dangerous if the infection spreads.

Call us right away if the redness and swelling are spreading or if you have:

  • Fever
  • Chills
  • Nausea
  • Vomiting


You may have sores or rashes, or the skin around the infection may be:

  • Red
  • Swollen
  • Warm or hot to the touch
  • Tender or painful

If the redness or swelling spreads, call us right away. It’s very important to stop cellulitis from spreading to your blood or organs.

Watch for other signs of infection:

  • Fever or chills
  • Swollen lymph glands
  • Fluid oozing from the infection
  • Feeling ill or very tired
  • Tight, stretched-looking skin
  • Aches or swelling in the joints
  • Nausea or vomiting

Adults usually have cellulitis on their arms, legs, or face. Children usually have it around their eyes or anus.

Symptoms that affect the eye. Cellulitis around the eye or in the eye socket (orbit) is called orbital cellulitis. This serious infection occurs most often in children. It must be treated immediately.


We usually diagnose cellulitis by giving you a physical exam and asking about your symptoms. Tell us about any recent injuries or skin problems, even if they seem minor.

We may draw a line around the red area on your skin and check the line every 24 hours. This tells us whether the infection is spreading. After you begin treatment the redness may continue to spread for a day or so.

Causes and Risk Factors


  • Is caused by bacteria (usually Staphylococcus or Streptococcus) that enters your body through a cut or break in your skin that may be too small for you to notice.
  • Infects the tissues below your skin.

Cellulitis can start in skin that is:

  • Cracked or peeling.
  • Affected by athlete’s foot or jock itch.
  • Irritated by clothing or shoes.
  • Broken by insect stings or animal or human bites.
  • Affected by eczema, acne, or psoriasis.

Your risk for cellulitis is higher if you have:

  • Recently had surgery.
  • An illness or take a medication that weakens your immune system or causes blood circulation problems. 

You can also get cellulitis through contact with raw meat, soil, or other substances that carry bacteria.


With proper treatment and self-care, your cellulitis will probably get better within 7 to 10 days.

We recommend that you:

  • Get plenty of rest.
  • Keep your body and clothing clean.
  • Keep the infected area clean and protected.

If you need antibiotics, we:

  • Usually prescribe 7 to 10 days of medication that you take by mouth.
  • Use intravenous (IV) antibiotics for severe infections, or if you don’t get better with oral medication.

Antibiotic treatment may take longer to work if you have a:

  • Chronic illness
  • Weakened immune system
  • Severe case of cellulitis

We can recommend pain medication if needed.

To reduce swelling, prop the swollen area on pillows so that it’s higher than the level of your heart.

Surgery may be needed to drain an abscess caused by cellulitis.


The best way to avoid cellulitis is to take good care of your skin. To prevent breaks, cuts, and scratches:

  • Use lotion or ointment that’s designed to keep your skin moist and prevent cracking.
  • Don’t scratch itchy or dry skin.
  • Wear well-fitting shoes that don’t cramp your feet.
  • Wear protective clothing and gear for work or sports.
  • Check your feet and skin daily for sores if you’re diabetic.
  • Treat fungal infections, such as athlete’s foot, right away.

When you have a cut or break in the skin: 

  • Clean it carefully with soap and water.
  • Cover it with a bandage.
  • Change the bandage daily until a scab forms.
  • Watch for redness, pain, drainage, or other signs of infection.

Please let us know if you have questions about keeping your skin healthy.


If cellulitis has spread to your organs or blood, you may need IV antibiotic treatment. Cellulitis can be life-threatening at this level.

Very rarely, we may need to treat and monitor you in the hospital. This may be necessary if you have:

  • An infection that has spread to your blood, lymph nodes, or organs.
  • A high temperature.
  • Blood pressure problems.
  • Nausea and/or vomiting.
  • A weak immune system because of a condition like cancer.
  • Infection in your eyes.

Your Care with Me

If you are having symptoms that concern you, your first contact will typically be with your personal physician, who will evaluate your health and symptoms.

If specialty care is needed, your personal physician will facilitate the process of scheduling an appointment in my department. If appropriate, she or he might call me or one of my colleagues while you are in the office so we can all discuss your care together. If we decide you need an appointment with me after that discussion, we can often schedule it the same day or soon thereafter.

During your office visit, we will discuss your medical and family history and I will perform a physical exam. I will explain the findings of your exam and answer any questions or concerns you may have. We will discuss treatment options and develop a treatment plan that is right for you.

If you need to talk with me after your visit or procedure, please call my office. You can also e-mail me with nonurgent issues from this website whenever it is convenient for you.

For general medical advice, our Appointment and Advice line is available 24 hours per day, 7 days per week.

If you have urgent concerns or issues while my office is closed, or need general medical advice, you can call the Appointment and Advice line. You will be connected with a nurse who can give you immediate advice.

If you are experiencing a serious problem or an emergency, call 911 or go to the nearest Emergency Room when the clinic is not open.

Coordinating Your Care

Having all of our Kaiser Permanente departments located together or nearby, including pharmacy, laboratory, radiology, and health education, makes getting your care easier for you.

Another major benefit is our comprehensive electronic medical record system, which allows all of the doctors and clinicians involved in your care to stay connected on your health status and collaborate with each other as appropriate.

When every member of the health care team is aware of all aspects of your condition, care is safer and more effective.

If you come to an office visit
  • At the beginning of your visit, you will receive information about when you are due for your next test, screening, or immunization. We can discuss and schedule any preventive tests that you need. 
  • At the end of your visit, you may receive a document called the “After Visit Summary” that will summarize the issues we discussed during your visit. You can refer to it if you forget what we discussed, or if you just want to recheck your vital signs and weight. You can also view it online under Past Visits.
  • To help you prepare for your visit, please see additional details under Office Visit. 
If I prescribe medications

We will work together to monitor and assess how your medications are working and make adjustments over time. Prescriptions can be filled at any Kaiser Permanente pharmacy. Just let me know which pharmacy works best for you, and I will send the prescription electronically in advance of your arrival at the pharmacy.

If refills are needed in the future, you can:

  • Order them online or by phone. Order future refills from my home page or by phone using the pharmacy refill number on your prescription label.
  • Have them delivered to you by mail at no extra cost. Or you can pick up your medications at the pharmacy. If no refills remain when you place your order, the pharmacy will contact me regarding your prescription.
If lab testing or imaging is needed

For lab tests, I will use our electronic medical record system to send the requisition to the Kaiser Permanente laboratory of your choice. For imaging procedures, we will schedule an appointment with the Radiology department. When the results are ready, I will contact you with your results by letter, secure e-mail message, or phone. In addition, you can view most of your laboratory results online, along with any comments that I have attached to explain them.

If I refer you to another specialty colleague

If we decide together that your condition would also benefit from the care of other types of specialists, our staff will help arrange the appointment(s) with one or more of my specialty colleagues.

If surgery or a procedure is a treatment option

I will recommend that you review educational information and tools to help you prepare for your procedure or surgery. The information will often help you decide whether surgery is right for you. If you decide to have a surgery or procedure, the information will provide details about how to prepare and what to expect.

If we proceed with surgery, I will have my Surgery Scheduler contact you to determine a surgery date and provide you with additional instructions regarding your procedure. Once your surgery is scheduled, a medical colleague of mine will contact you to conduct a preoperative medical evaluation that will assure that you are properly prepared for your surgery.

Convenient Resources for You

As your specialist, I have a goal to provide high-quality care and to offer you choices that make your health care convenient. I recommend that you become familiar with the many resources we offer so that you can choose the services that work best for you.

My Doctor Online is available at any time that is most convenient for you. From my home page you can:

Manage your care securely
  • View and compose secure e-mail messages.
  • Manage your prescriptions.
  • View your past visits and test results.
  • View your preventive services to see whether you are due for a routine screening or updated immunization.
Learn more about your condition
  • Read about causes, symptoms, treatments, and procedures.
  • Find interactive health tools, videos, and podcasts to help you manage your condition.
  • View programs to help you decide on or prepare for a surgery or procedure.
Stay healthy
  • Locate health education classes and support groups offered at every medical center.
  • Explore interactive programs, videos, and podcasts that focus on helping you stay healthy.
  • View your Preventive Services to see whether you are due for a routine screening or updated immunization.

If you have an emergency medical condition, call 911 or go to the nearest hospital. An emergency medical condition is any of the following: (1) a medical condition that manifests itself by acute symptoms of sufficient severity (including severe pain) such that you could reasonably expect the absence of immediate medical attention to result in serious jeopardy to your health or body functions or organs; (2) active labor when there isn't enough time for safe transfer to a Plan hospital (or designated hospital) before delivery, or if transfer poses a threat to your (or your unborn child's) health and safety, or (3) a mental disorder that manifests itself by acute symptoms of sufficient severity such that either you are an immediate danger to yourself or others, or you are not immediately able to provide for, or use, food, shelter, or clothing, due to the mental disorder.

This information is not intended to diagnose health problems or to take the place of specific medical advice or care you receive from your physician or other health care professional. If you have persistent health problems, or if you have additional questions, please consult with your doctor. If you have questions or need more information about your medication, please speak to your pharmacist. Kaiser Permanente does not endorse the medications or products mentioned. Any trade names listed are for easy identification only.

Content loading spinner