Where there is eczema, there is a rash, which is a visible outbreak on the skin. There are many different types of rash, and if, like me, you’re not a doctor, correctly identifying them can be extremely difficult and frustrating.
However, it’s also important to know your rashes, especially if you have children. One way of identifying rashes is to divide them into different categories, starting with infectious or noninfectious.
Noninfectious rashes
Eczema is a classic noninfectious rash. In this category, you will also find:
- contact dermatitis
- psoriasis
- seborrheic dermatitis
- rosacea
- hives (urticaria)
- dry skin (xerosis), and
- allergic dermatitis.
Many noninfectious rashes can be treated with corticosteroid creams and/or pills. While they are not contagious and not infectious, they can be extremely unpleasant, and you shouldn’t wait to seek relief and treatment.
Eczema or atopic dermatitis are catch-all terms for a wide variety of skin sensitivity. They are characterized by areas of skin that become dry, red, and itchy. There’s more on identifying eczema, here.
Allergic reactions are also a significant cause of non-infectious rashes. Many people may react to exposure to drugs that contain penicillin, for example. Food allergies can sometimes be seen in the form of hives, and there’s more about how food can affect rashes for better and worse here.
An individual might develop contact allergic dermatitis as a result of repeat exposure to topical products. Allergic reactions to adhesives, some metals, such as nickel, cobalt, some fragrances, and latex are typical, but any substance has the potential to induce a skin allergy.
Cleaning chemicals, including some harsh, commercial soaps, can give rise to irritant dermatitis because they can cause your skin to get too dry. But it’s not just commercial products that can irritate the skin; repeated exposure to poison oak and poison ivy can lead to the development of hypersensitivity or allergic dermatitis, and other allergens such as grass can cause hives in some people.
More information on allergens, and environmental irritants can be found in the linked articles.
Miliaria or heat rashes occur – especially after repeated sweating in a hot, humid environment – when sweat is trapped in the skin by blocked pores and causes inflammation and itching. The rash looks like very small bumps that may be pinkish or clear, similar to gooseflesh. Miliaria is very common in infants and may also occur in adults.
Non-infectious rashes can be unpleasant and painful, so it’s best to take them to your doctor as soon as possible.
While short term steroid use is sometimes essential, it is best avoided long term because it can lead to thinning of the skin. The advice here is the same as ever: avoid irritants and allergens, avoid harsh detergents and use natural products (including gentle soaps), as much as possible.
Infectious rashes
Medical professionals treat these conditions by focusing on the root of the problem. When it comes to infectious rashes, that includes: viruses, bacteria, fungi, and parasites. The skin is very good at defending itself, so contagious skin conditions don’t always require skin to skin contact, and that’s why the largest group of common skin rashes are viral.
Kids are particularly susceptible to viral infections and illnesses, so if your little one has a rash, a viral infection should be a serious consideration. Though rare, thanks to vaccination, measles is the classic viral rash. And you may be familiar with roseola, which affects infants and is preceded by very high fevers and a bright red rash on the trunk.
When a rash is potentially infectious is always a good idea to reduce skin contact with others and consult a doctor.
Viral skin rashes
- Measles (morbilli)
- German measles (rubella)
- Chickenpox (varicella)
- Epstein-Barr virus (EBV)
- Papular purpuric gloves and socks syndrome (parvovirus)
- Roseola (erythema subitum, due to herpes virus 6 and 7)
- Enterovirus infections, including hand, foot and mouth disease.
- Herpes viruses, simplex, zoster and shingles
- Viral meningitis
Herpes simplex (HSV) types I and II can cause infections of the nose, lips, facial skin, buttocks, and genitals. Herpes zoster causes chickenpox and shingles.
HIV is a cause of many kinds of rashes, including viral and infection-associated rashes, and noninfectious drug rashes for those receiving treatment for HIV.
Epstein-Barr virus (EBV) is associated with many rashes, mononucleosis being the most common.
And many other viruses cause rashes. Coxsackievirus, for example, is associated with hand, foot, and mouth disease (HFMD), while parvovirus infections can lead to a variety of rashes.
Common bacterial infections
- Impetigo
- Staphylococcus infections, or Erysipelas
- Folliculitis
- Lyme disease
Examples of Bacterial Infections
The popularity award for bacterial infections goes to staphylococcus. Staphylococcus infections are the cause of many types of rashes. These include abscesses, cellulitis, folliculitis, and impetigo.
A streptococcus infection is the one that might lead to strep throat. It can also be at the root of cellulitis, scarlet fever, necrotizing fasciitis, and other skin nasties.
Lyme’s disease is a kind of bacterial infection, too. It can be mistaken for ringworm at first because it has a red ring that slowly expands, but it won’t normally have the accompanying scaliness afterward, and often has a pale center, which is why it is also called a ‘target rash’.
There are plenty of bacteria that keep our skin on high alert, but red alerts for skin do not stop there.
A bacterial infection of the skin can also occur around an area of broken skin, but these are typically local to the wound. They probably don’t sound very important, but they can lead to sepsis, when the bacteria spreads around the whole body, including the vital organs, so it’s important to get treatment.
Some people are more at risk in these cases, than others:
- People who have diabetes
- People who are older
- People who have HIV and other immune disorders
- People taking long term steroids or chemotherapy that leave their immune system compromised.
Examples of fungal rashes include
- Trichophyton is a kind of skin fungus that frequently causes skin rashes. The rash is called called tinea or ringworm and may occur anywhere on the body.
- Candida can cause yeast infections. These occur in moist areas of the body, typically where the skin is folded, such as between fingers and toes, in your mouth, and your groin.
There are other fungal infections, of course, but they are less common. They include cryptococcosis, aspergillosis, and histoplasmosis. They are more likely to occur in people with a compromised immune system than a healthy person. People who have travelled may be exposed to other kinds of fungal infection, particularly if they have visited the tropics.
Examples of Parasitic Infections
A parasite is something that a) lives on or in another organism and b) benefits from nutrients at the host’s expense.
A very itchy, skin infestation might be scabies. This is contagious and involves a microscopic mite.
Lice infestations may also cause itchy rashes. With lice, these are likely to appear on the scalp, at the nape of the neck, or in the pubic area.
Preventing the spread of infection
While not all infectious rashes are spread by direct contact, if someone in your household has an infectious rash, it makes sense to keep their personal items, such as towels and soaps, separate from everyone else’s. Because rashes can often be sensitive, be sure to use only the gentlest, natural soaps when bathing.
What kind of rash do I have?
If you’ve encountered the rash before and a treatment worked, this can also be a clue as to what kind of rash it is.
And don’t discount your history and family history. A family history of eczema, for example, may point toward your rash being eczema. If you’ve recently used a new medication or skincare product, these may have led to you developing a rash. Think carefully about products you have consumed or used on your skin. If necessary, monitor these in a diary to see if there is a link between what you eat or use, or where you have been, and a rash.
Rashes are also common before, during, and after pregnancy. While most of these are not serious, they can be uncomfortable and are worthy of medical attention.
Classifying rashes according to their cause is one system, but if you have no idea of the cause, then you can also consider its appearance, including its shape, arrangement, and distribution, and also think about its duration, your symptoms, and your medical history. Being able to tell your doctor how the rash has progressed will make their job easier, as will keeping a journal about your rash, and we’ve got some advice on that here.
Right, I’m off to find a mirror and look at that itch on my back!!
