SerahP Asked :

I developed a little boil on my leg  just above my knee about 2 weeks back and it was really itchy. I tried not to scratch but I could not help it. After a few days it started to get very itchy and swollen and I went to see my doctor who said it was a spider bite. Apparently this is a problem in our region from what my doctor says. He put me on some meds that reduced the itchiness but did not stop it.

A few days later I started noticing red patches on my skin. It was coming up the thigh and forming inwards towards the groin. These red patches were tender to touch and felt lumpy. After that a fever started up and felt really miserable. My leg was swollen and painful, mainly the thigh. My doctor diagnosed me with cellulitis and put me on a heavy dose of antibiotics and a cream.

I have finished the antibiotics 3 days back but the leg swelling and red patches are still there although reduced. The leg is not all that painful anymore but the red patches are still tender. The boil or abscess has gone down quite a bit and is surrounded by a dark brown ring but its still painful with a lot of  itchiness around it.

Do you think that I am having an allergic reaction to the bite? How long before all this goes down completely?


This question was posted under the Swollen Leg and Swelling of the Feet, Ankle, Toes article.

Any response by the Health Hype team does not constitute a medical consultation and the advice should be viewed purely as a guide. Always consult with your doctor before making any changes to your current treatment program. The information provided in this article is not an authoritative resource on the subject matter and solely intends to guide the reader based on the questions asked and information provided.


Dr. Chris Answered :

The spider bite may have become infected from scratching the area as bacteria are transferred from your hands to the site or bacteria on the skin of the leg entered the area. It is important that you try to restrain yourself from scratching the area and speak to your doctor about creams to reduce the itching around the abscess. You will need to continue using the antibacterial cream on the abscess itself.

The red tenderness crossing your thigh is possibly related to the bacterial infection. This may correspond with the lymph nodes of the thigh which are now swollen and inflamed (‘feeling lumpy’). As long as you have completed your antibiotics as prescribed, the infection should go down but these red patches and swollen lymph nodes can take up to  a week or two to settle down. If not, hospitalization and IV antibiotics may be necessary.

If it was an allergic reaction to the spider bite then you would have seen other signs and symptoms which would have occurred shortly after the bite. This may have triggered angioedema which could have been accompanied by other symptoms ranging from urticaria (hives) to narrowing of the air passage, leading to shortness of breath in severe cases. In all likelihood, from what you say, you caused the infection a few days after the bite, most likely due to your scratching. However, an allergic reaction cannot be ruled out and this should be determined by your doctor.

Cellulitis is a serious complication and the symptoms can take 10 to 14 days to settle down. It is imperative that you see your doctor and confirm that the infection has resolved or the condition may flare up again and can lead to further complications. The skin around the abscess may also be inflamed and this can be felt as itching. The inflammation is also contributing to the leg swelling. The dark ring may be some necrotic tissue (What is necrosis?) and it is important to take note if this is spreading. If you are healthy with no pre-existing conditions that can affect immune functioning,  then this should resolve spontaneously. There may be some scarring in the area in the long term.

Rather be cautious and see your doctor as soon as possible to ensure that there are no other complications.


Article reviewed by Dr. Greg. Last updated on May 18, 2010