Our skin is more than just a physical barrier - it is a frontline defence against microorganisms, toxins and infections.
But even the strongest armour can be breached.
Skin and soft tissue infections (SSTIs) are relatively common health concerns that range from minor irritations to life-threatening conditions.
And often, they begin with something as small as a scratch or an insect bite.
These infections are caused by a variety of bacteria and other microorganisms that enter the skin through wounds, burns and other injuries.
Risk factors for developing SSTIs include diabetes, immunodeficiency disorders and chronic oedema.
These infections can be diagnosed based on the appearance of the lesions, degree of pain and by identifying the bacteria.
A furuncle (boil) is a skin infection involving an entire hair follicle and nearby skin tissue.
They are generally caused by the bacterium Staphylococcus aureus.
They can be single or multiple, and occur most commonly on the face, neck, armpit and thighs.
A furuncle may begin as a tender, pinkish-red, swollen nodule, but ultimately feel like a water-filled balloon or blister.
It will cause pain and discomfort that gets worse as it fills with pus and dead tissue.
After an initial period of itching and mild pain, more often than not, they will burst, drain and then heal on their own.
Bursting the furuncle on your own increases the risk of another infection and could delay healing.
The fluid-filled blister actually keeps the underlying skin clean, which prevents further infection and promotes healing.
A carbuncle is a cluster of boils that form a connected area of infection under the skin.
It often involves a group of hair follicles.
The infected material forms a lump, which occurs deep in the skin.
Similar to furuncles, most carbuncles are caused by S. aureus.
The infection is contagious and may spread to other areas of the body or other people.
Carbuncles usually drain before they heal.
This most often occurs on its own in under two weeks.
Placing a warm moist cloth on the carbuncle helps it to drain, which speeds healing.
Impetigo is a skin infection that usually produces blisters or sores on the face, neck, hands and the diaper area.
It is one of the most common skin infections among kids.
It is usually caused by S. aureus, but can also be caused by infection with group A Streptococcus.
Impetigo is contagious and can spread to anyone who comes into contact with the infected skin or contaminated items such as clothing, towels and bed linens.
There are two types of impetigo: bullous impetigo (large blisters) and non-bullous impetigo (crusted).
The non-bullous form is more common.
It begins as tiny blisters that eventually burst and leave small wet patches of red skin that may weep fluid.
Gradually, a tan or yellowish-brown crust covers the affected area, making it look like it has been coated with honey or brown sugar.
Bullous impetigo triggers larger, fluid-containing blisters that appear clear, then cloudy.
These blisters are more likely to stay intact longer on the skin without bursting.
Cellulitis
This patient has cellulitis of the left leg, which is also oedematous (i.e. swollen due to fluid retention).
Cellulitis is a common infection of the lower layers of skin (dermis) and the subcutaneous tissues.
It usually begins as a small area of pain and redness on the skin.
This area spreads to surrounding tissues, resulting in the typical signs of inflammation, i.e. redness, swelling, warmth and pain.
It is most commonly caused by the bacteria Streptococcus pyogenes and Staphylococcus.
It often occurs where the skin has previously been broken, e.g. cracks in the skin, cuts, blisters, burns, insect bites, surgical wounds or sites of intravenous (IV) catheter insertion.
Treatment requires resting the affected limb or area, cleaning any wound site (with removal of dead tissue if necessary) and treatment with oral antibiotics.
Severe cases may require hospital admission and IV therapy.
ALSO READ: A simple cut could put you at risk of this dangerous skin infection
Folliculitis
Folliculitis is inflammation of one or more hair follicles.
It can occur anywhere on the skin and is often caused by Staphylococcus.
Common symptoms include a rash, itching, and pimples or pustules near a hair follicle in the neck, groin or genital area.
Cat scratch disease is spread through contact with an infected cat (via a bite or scratch), or contact with cat saliva on broken skin or the white of the eye.
The disease is caused by the bacterium Bartonella henselae.
A blister or sore, with or without pus or fluid, often shows up on the skin at the place where the bacteria entered the body.
About two to three weeks after infection, lymph node swelling (lymphadenopathy) will occur near the site of the scratch or bite.
Occasionally, an infected lymph node may form a tunnel (fistula) through the skin and drain (leak fluid).
Cat scratch disease is a common cause of chronic swollen lymph nodes in children.
Generally, this disease is not serious and medical treatment is not usually needed.
However, in severe cases, treatment with antibiotics can be helpful.
Erysipelas is a superficial infection of the skin that typically involves the lymphatic system.
It is most often caused by Group A Streptococcus bacteria.
It tends to occur in areas where the lymphatic system is obstructed.
Erysipelas causes a fiery red rash with raised edges that can be easily distinguished from the skin around it.
It is treated with antibiotics.
The rash of erysipelas can always be clearly distinguished from normal skin, as seen in this case involving the patient's ear. -- Wikimedia Commons
Scalded skin syndrome
Scalded skin syndrome most commonly affects infants and children under the age of five years.
When it occurs in a newborn, it is called Ritter's or Lyell's syndrome.
The syndrome is caused by an exfoliative toxin produced by S. aureus.
This toxin causes the outer layers of skin to separate from the inner layers, enabling the formation of large, thin-walled blisters.
When these blisters burst, the underlying skin looks like it has been scalded.
This infection can be life-threatening and needs quick treatment.
This usually requires a hospital stay, often in the burn or intensive care unit (ICU).
Treatment includes antibiotics, replacing fluids and skin care.
Children who get prompt treatment usually recover with no scarring or complications.
Toxic shock syndrome
Toxic shock syndrome is caused by a toxin produced by Staphylococcus bacteria.
It is usually associated with use of highly-absorbent tampons.
Symptoms include a large, flat, red rash that looks like a sunburn, diarrhoea, nausea and vomiting, feeling generally ill, headaches, high fever and low blood pressure, among others.
It can lead to organ failure (usually the kidneys and liver) if not treated promptly.
Antibiotics are given, and any foreign materials, such as tampons, vaginal sponges or nasal packing, need to be removed.
Necrotising fasciitis
Necrotising fasciitis, commonly known as flesh-eating disease, is a rare infection of the deeper layers of skin and subcutaneous tissues.
It is mostly caused by the bacteria S. pyogenes, S. aureus and Bacteroides fragilis.
The infection begins at the site of trauma to the skin and is more common in patients with diabetes.
Patients usually present with the triad of exquisite pain, swelling and fever.
Tenderness, redness and warm skin are commonly the only signs of early necrotising fasciitis.
As the disease progresses, the tissue becomes swollen, often within hours.
Diarrhoea and vomiting are also common symptoms.
Initial treatment often includes a combination of IV antibiotics.
Aggressive surgical debridement (removal of infected tissue) is always necessary to keep it from spreading and is the only treatment available.
Gas gangrene
Gas gangrene, or clostridial myonecrosis, is an infection of muscle tissue where gas is produced within gangrenous tissues.
It presents with a foul-smelling discharge and is a deadly form of gangrene.
It is caused by the introduction of the bacterium Clostridium perfringens or its spores into a wound or incision.
The site of infection becomes inflamed with a pale to brownish-red and very painful tissue swelling.
Pressing on the swollen tissue may produce a crackly sensation.
The edges of the infected area expand so quickly that changes are visible within a few minutes.
The involved tissue is completely destroyed.
If the condition is not treated, the patient can develop a shock-like syndrome with decreased blood pressure (hypotension), kidney failure, coma, and finally, death.
The patient will need to have surgery quickly to remove the affected tissue (debridement).
Surgical removal (amputation) of an arm or leg may be needed to control the spread of infection.
SSTIs are very common, however, there are many preventive measures we can take to avoid these infections, such as:
Our skin is a remarkable organ, resilient yet vulnerable.
While many bacterial skin infections are treatable, some can be dangerous if ignored.
Infections don't discriminate, even the smallest lapse in hygiene or an unnoticed wound can open the door for bacterial infection.
By maintaining cleanliness, being vigilant about wounds and adopting a healthy lifestyle, we can protect our skin, and ultimately, our health.
Let's treat hygiene not just as a habit, but as a daily commitment to better living.
Your skin will thank you.