Erysipelas and cellulitis

Both infections are most common on the feet or lower legs, but they may also occur in other areas of the body. Erysipelas can develop on the face, and cellulitis may also occur on the palm of the hand, for instance.

Erysipelas affects the outer layers of the skin. It typically leads to painful swelling in a quite clearly defined area of skin. On lighter skin, this area looks shiny and light red. Red streaks leading from that area may be a sign that the infection has started to spread along the lymph vessels too. On darker skin, the redness is less noticeable or can't be seen at all. The darker the skin, the harder it is to see. In more severe cases of erysipelas, blisters may form as well.

Nearby lymph nodes sometimes swell up and hurt when touched. People usually have a fever and feel generally unwell right from the start of the infection.

Unlike erysipelas, the infection caused by cellulitis reaches deeper layers of skin and the connective tissue beneath it. It can spread along tendons and muscles, and pus may form. If any redness can be seen, the area is less clearly defined than in erysipelas. On lighter skin it often looks dark red or light purple in color.

Like in erysipelas, the affected skin and connective tissue is typically swollen and painful in cellulitis. But people are less likely to develop a fever or feel unwell. That might happen in more serious cases of cellulitis, though.

Both types of infections are caused by bacteria that get in through breaks in the skin. Erysipelas is often caused by streptococcus bacteria, while cellulitis is typically caused by staphylococcus bacteria. Both types of bacteria can cause either erysipelas or cellulitis, though.

Damage to the surface of the skin makes it easier for bacteria to get in. Because of this, the risk factors include

• skin problems like eczema, impetigo and athlete's foot,
• wounds and ulcers,
• injuries such as pin pricks,
• insect or animal bites, and
• operations where germs got into the wound.

The risk of infection is particularly high if you have a weakened immune system – for example, as a result of taking certain medications. These include some cancer drugs, steroids, and medications that are used in the treatment of autoimmune diseases like rheumatoid arthritis (to suppress the body's immune response).

Various other health problems can also increase the risk of developing erysipelas or cellulitis. These include diabetes, being very overweight, problems with the drainage of lymph fluid or the circulation of blood, and venous insufficiency. People who have had erysipelas or cellulitis in the past are more likely to develop it in the future.

Erysipelas and cellulitis are among the most common skin conditions, but it's not known exactly how often they occur. According to some studies, 2 out of 10,000 people are affected each year. Other research suggests that more than 250 out of 10,000 people are affected.

If left untreated, bacterial skin infections can lead to various complications. These include the following:

• The spread of pus-producing infection and abscesses: Especially in cellulitis, the infection with pus can spread to deeper tissue (such as muscle tissue). Sometimes the pus builds up in natural spaces or gaps between tissue, leading to abscesses.
• Lymphedema: The infected lymphatic vessels may be badly damaged in some places after an erysipelas infection. Then the lymph fluid can't drain properly, causing it to build up. That leads to a permanent swelling known as lymphedema. The blood circulation in the tissue becomes worse as a result, increasing the risk of another bacterial skin infection.

Life-threatening complications are rare. If bacteria enter the bloodstream, they may cause blood poisoning (septicemia). In very rare cases, a bacterial skin infection on the face can cause meningitis ( inflammation of the membranes covering the brain and spinal cord) or a blood clot in one of the blood vessels in the brain (cerebral venous thrombosis).

If there are complications, they have to be treated fast. Signs of a more severe infection include

• severe pain,
• fever, cold sweats, pale skin,
• nausea,
• a faster rate of breathing or a racing heart, and
• drowsiness, confusion, or other problems affecting consciousness or awareness.

Doctors can usually tell whether an infection is erysipelas or cellulitis based on the typical symptoms. The appearance of the skin is often enough to make a clear diagnosis, particularly on lighter skin. Your medical history or recent injuries often help to diagnose the problem too.

Further tests aren't usually needed. Sometimes the fluid from the wound is tested for germs. Knowing exactly what kind of bacteria is causing the infection can be important for the treatment.

People who have had erysipelas or cellulitis in the past are more likely to develop the same kind of infection in the future – even after successful treatment. About one third of people who have had an erysipelas infection get it again.

Avoiding damage to your skin is one way to reduce the risk. If a skin condition like athlete’s foot or eczema made it easier for the infection to occur in the first place, it is a good idea to treat that condition first. People who have diabetes or blood circulation problems are more likely to have injuries on their feet and legs. That also increases their risk of infections in those places. So it's important for them to take good care of their feet.

If bacterial skin infections keep occurring, preventive treatment with antibiotics may be considered. The antibiotics are then taken daily over a number of months.

Erysipelas and cellulitis are both treated with antibiotics like penicillin. The medication is delivered directly into a vein using a drip. In milder cases, the antibiotics can be taken in the form of tablets instead. People who go to the hospital for treatment usually have to stay for about a week.

The choice of antibiotic will depend on several factors, like what type of bacteria the doctor thinks you have (or what type of bacteria they have identified). To check if the treatment is working, the healthcare professional outlines the visible area of infected skin with a special pen. That way, they can see if the infection is starting to go away and the antibiotics are helping.

Doctors also recommend that you cool the swelling and apply moist antiseptic (germ-killing) dressings. Anti-inflammatory painkillers like ibuprofen can help to reduce pain and fever.

If the infection is on your face, it's better to speak or chew as little as possible. If the skin on a leg or foot is infected, it's a good idea to keep that leg raised. Bed rest is even recommended in many cases.

In severe cellulitis, surgery is needed in order to remove pus and dead tissue.

When people are ill or need medical advice, they usually go to see their family doctor first. Information about health care in Germany can help you to navigate the German healthcare system and find a suitable doctor. You can use this list of questions to prepare for your appointment.