Spreading of Contagious Impetigo Rash, Treatment and Incubation Period

Impetigo is a bacterial infection that occurs on the skin. It is most common in children aged between 2 and 5 years old. The infection usually appears on the face but can also occur in the arms, legs and basically any part of the skin. Although infection mostly starts around an injured area, bacterial colonies can also build on a healthy body area. It is also possible to have impetigo on fingers.

Most cases present with small red papules that soon develop into blisters and form yellow or brown crusts. A less common type of impetigo causes large blisters which may be painful and itchy on the buttocks, trunk, armpit or groin. Normally, impetigo is not a serious infection. It can clear even without treatment in about six days. Complications such as blood poisoning and cellulitis can make the infection serious.

Treatment is mainly done with antibiotics. The severity of infection determines the type of medications to be given although ointments are most commonly used. Home treatment with remedies and preventive measures are also available.

How do you get impetigo?

So how do you get impetigo? People get impetigo when staphylococcus or streptococcus bacteria build colonies in the epidermis, which is the outermost skin layer. In most cases, causal bacteria are picked up from an infected person or from contaminated surfaces. Skin discontinuities and injuries often provide portals of entry, although an infection can begin in healthy skin.

A number of factors make the risk of getting impetigo higher. They however do not necessarily cause the infection. These factors include:

  • Age – the incidence rate is highest in children aged 2-5 years.
  • Certain environmental conditions – bacteria survive best in wet and warm conditions. It is for this reason that most impetigo cases are reported in summer and winter.
  • Weakened immunity – people with diseases such as diabetes and HIV often have a weakened immune system. This means that pathogens have an easier time building colonies in the body.
  • Skin injuries – injuries on skin such as cuts, sores or conditions like eczema make it easier for bacteria to gain access into the skin.
  • Congested places – impetigo for example spreads very fast in schools. Sports that allow direct skin to skin contact also spread impetigo.

Impetigo in dogs or other pets can also pass to humans. Having a risk factor doesn’t guarantee that a certain disease will develop. More information can be found here what causes impetigo.

Is impetigo contagious?

Is impetigo contagious? Impetigo is highly contagious. It is for this reason that affected kids are advised to not attend school until after later stages.

People with impetigo easily pass bacteria to other people during direct contact. If a skin injury is present, chances of developing infection increase. Contaminated surfaces such as toys, clothing and personal hygiene items can also carry bacteria from one person to another.

Other than passing impetigo to other people, patients can also spread the infection to other body areas. This is especially after scratching or touching affected areas. About 20% of all healthy people are carriers of staphylococcus bacteria in the area between genitals and anus. These bacteria can be passed to other body areas where they may cause infection. Bacteria living in the nasal passages may cause recurring cases of impetigo.

Impetigo is most contagious once papules have burst open to form open sores. Both the surface and yellow clear fluid that oozes from burst sores are rich sources of bacteria. Once the sores have crusted over or formed scabs, transmission rate drops significantly.

Patients rarely transmit infection 48 hours after starting treatment with antibiotics. This is partly why seeking medical attention is encouraged even though impetigo is not a serious disease.

How to identify impetigo rash and blisters

There are two main types of impetigo, bullous and nonbullous.

  • Bullous – this is the less common type. It can develop even on intact skin areas. Once bacteria are inside the skin, they release toxins which cause a separation between epidermis and dermis. This results in larger blisters which may be painful. Staphylococcus bacteria are responsible for this type of impetigo.
  • Nonbulluos – this is the more common type. It develops in areas around an injury or discontinuity where bacteria have gained access into the skin.

Another form of impetigo known as ecthyma causes results in a more serious infection. It occurs when bacteria reach deeper skin tissues. Strep bacteria are mostly responsible.

Nonbullous impetigo causes papules that remain flattened but gain peripheral size. Soon, the papules burst to release pus or a yellowish fluid. The fluid dries up to form a honey-colored crust. Resulting itchiness may spread infection to adjacent areas after the patient scratches the affected area. This causes new papules which go through the same process. Scratching can also cause scarring.

Formation of crusty lesions is a classic defining feature in erysipelas vs impetigo. Unlike impetigo, erysipelas forms well defined borders with brilliant red coloration.

Signs and symptoms to look for:

Small red papules or vesicles are the classic signs of impetigo. These quickly rupture leaving a brown or yellowish crust. While the soreness is mild and not painful, itchiness is usually present. The sores heal even without treatment in about 6 days. Scarring is often not present after recovery. This type usually appears on areas around mouth and nose.

Bullous impetigo causes transparent blisters that may reach 3 cm in diameter. A yellow clear fluid which may turn dark fills the blisters and may ooze after rupturing. Bullous impetigo blisters are delicate and rupture after 2-3 days. Patients may experience fever, nausea and lethargy. This type often affects the buttocks and trunk. One can also get bullous impetigo on chin, arms or groin.

Impetigo rash incubation period

Impetigo rash takes at most 2 weeks to clear. This period can be lessened with medications. How long is impetigo contagious? In the first 2-3 days after blisters have formed, impetigo is most contagious. The crusts that form over ruptured blisters render impetigo noncontiguous.

Bullous impetigo may have a longer incubation period. How long does impetigo last? Without treatment, the whole process from infection to full recovery can take up to 14 days. Most of the serious symptoms will have improved by the second week.

People taking medications stop being potential transmitters 2 days after embarking on treatment. Severe infections requiring treatment with IV medications may remain contagious for a little longer. Covering impetigo blisters with loose bandages may keep the infection from being transmitted.

Incubation period for strep infection is 1-3 days while that of staph infections is 4-10 days. Having a weak immune system or multiple infections may reduce the incubation period.

How is impetigo diagnosed?

Doctors usually recognize impetigo from signs and symptoms after physical examination. The patient’s medical history may aid in diagnosis confirmation.

If doubts exist, fluid culture can be taken. This helps identify the type of pathogen causing infection. Presence of bacteria can be checked in swabs or crusts.

Impetigo treatment

Impetigo treatment is mostly done with antibiotic ointments or creams such as bacitracin for impetigo. Impetigo treatment cream is to be applied directly until the infection is healed.

Oral antibiotics may be prescribed for more serious impetigo cases. Rarely will IV antibiotics be necessary.

Impetigo treatment at home

At home, impetigo natural treatment can be done with:

Heat therapy:

Heat therapy is one of the most popular home treatments for a wide range of infections and conditions. It involves pressing a thick piece of cloth soaked in hot water on affected areas. This treatment can be done several times a day until infection is completely healed. It discourages bacterial growth, draws pus towards the surface and promotes blood circulation.

Tea tree oil:

Tea tree oil has the ability to reduce inflammations and prevent microbial infections. Before use, it is important that carrier oil be used to dilute it. This is to avoid skin irritation. The oil can also be diluted with water. Daily direct application using a cotton swab is recommended.


Vinegar acts as a natural antiseptic. It may also relieve symptoms such as itchiness and pain. To use it, add a teaspoon of white vinegar to two cups of water. Use a cotton ball to apply directly. You can also use apple cider vinegar after diluting it with water.


Honey is a very powerful home remedy for treating wounds and burns. It relieves pain and keeps bacteria from multiplying. In fact, honey as a treatment for wounds has been used since ancient times. Manuka honey is thought to be most beneficial but raw honey can be used for the same effects.

Coconut oil:

Coconut oil is mostly known for its moisturizing benefits. However, it can also be used to stop bacterial growth. Coconut oil is mild and can be used even on sensitive skin and body areas. Direct application is recommended.


Garlic cloves crushed and fried in sesame oil may prove effective in treating impetigo. It can also be added to the diet.

How to care for and prevent impetigo

Care measures:

Keep wounds clean and dry.

Always make sure to wash affected areas with lukewarm water and medicated soap. This reduces the number of bacteria that may cause further infection. Dryness makes it impossible for bacteria to multiply.

Cover with a loose bandage.

A loose and waterproof dressing helps keep bacteria from spreading. It also prevents children from scratching affected areas. Always remember to change the dressing from time to time.

Observe personal hygiene.

Personal hygiene is very important, especially when a close family member has been diagnosed with impetigo. Sharing clothes and items like towels can easily spread the disease. In kids, parents should ensure to wash and change the kid’s linen.

See a doctor.

Complications of impetigo are not common. The disease often heals even without treatment. The problem is that lack of treatment increases chances of spread and possible complications. It is not worth it, bearing in mind that medications are widely available.


Promote hygiene.

If a family member has been diagnosed with impetigo, encourage other household members to regularly wash their hands with medicated soap if available. This helps flush out bacteria that may have been picked from contaminated surfaces.

Keep your child at home.

Impetigo is highly contagious, especially after the incubation period. Affected children should be kept from attending school or engaging in sports that allow skin to skin contact. Sharing of toys and personal items should also be discouraged.

Protect affected areas.

Touching and scratching affected areas is a classic way to spread infection. This can be discouraged by dressing with bandages and keeping fingernails short.

Possible complications of impetigo

Severe or untreated impetigo can lead to the following complications:

  • Cellulitis – this is a more serious and potentially dangerous bacterial infection. It affects deeper skin layers and thus not contagious. Signs include swelling, pain and redness. Cellulitis develops around injured areas.
  • Toxic shock syndrome – rarely will this condition be caused by impetigo. It is characterized by fever, low blood pressure and desquamating rash.
  • Scarlet fever – scarlet fever is mostly preceded by strep throat but can as well be a complication of impetigo. It causes red rash, high fever and sore throat.
  • Post-streptococcal glomerulonephritis – impetigo rarely leads to post-streptococcal glomerulonephritis. This is an infection of blood vessels that supply blood in kidneys. It occurs three to six weeks after infection. Signs include widespread swelling and blood in urine.

In pregnant women, a rare infection known as impetigo herpetiformis can occur.