Is Cellulitis Contagious?

My husband has been diagnosed with cellulitis. He is being treated with Keflex. Is cellulitis contagious? His leg is swollen, red and feverish but has no open sores. How serious is this?


Cellulitis is an infection of the skin and some underlying tissues. It usually occurs on an arm or leg, but it can occur anywhere on the body.


Typically, there is a small portal of entry for bacteria, such as a minor skin cut or even athlete's foot. The most common bacteria to cause cellulitis are various types of streptococci. Another cause of cellulitis is Staphylococcus aureus (known as "staph infection"). Less commonly, other bacteria and even fungi are responsible, but this more often occurs in diabetics and people whose disease-fighting immune system is depressed.


The symptoms of cellulitis are redness, warmth and moderate pain in the affected area. The patient may also have fever, chills and other whole-body symptoms. Occasionally, streptococci can invade deeper structures with very rapid progression. When the fascia, the tissue overlying the muscle, becomes infected and dies, the disease is called necrotizing fasciitis. This has been dubbed infection with "flesh-eating bacteria." The reason some people develop this life-threatening infection while others only develop cellulitis is not entirely clear. Part of the reason has to do with the strain (variety) of bacteria involved. Certain strains of strep can produce toxins that destroy tissue and cause severe illness.


Ordinary cellulitis is thankfully far more common than the more serious forms of skin infection. If a patient has the symptoms of cellulitis, does not appear very ill and does not have extreme pain in the area, the infection is usually simple, garden-variety cellulitis. The illness probably developed over days, as opposed to necrotizing fasciitis, which can progress over hours.


Treating cellulitis is rather simple. The patient should keep the affected limb elevated above his or her heart, if at all possible. Doctors should prescribe an antibiotic that is active against the usual disease-causing bacteria. Keflex (generic name cephalexin) is a cephalosporin antibiotic, related to the penicillins. It is usually effective for simple cellulitis, though I personally prefer a penicillinlike drug called dicloxacillin (trade name Dynapen). There are many choices that would probably all be equally effective. The response to the antibiotic should occur over several days.


In general, cellulitis is not contagious. However, the bacterium causing the infection can be spread from one person to another. If another person acquires the bacterium -- and remember that we are all covered with various types of organisms -- then he or she is at some risk of developing the same infection if the right circumstances exist, such as a minor injury of some sort. In the case of necrotizing fasciitis, since the infection is so severe and the strain so dangerous, special precautions should be taken to avoid the spread of the offending bacterium.


by Harold Oster