Rashes are common problems that affect many people throughout their lives. When it occurs in babies and children it is worrying for the mother or carer and a cause has to be identified to suggest the appropriate treatment. Rashes cause the skin to be abnormal in some way. It may appear red and may exhibit changes such as blisters, hives, drying, cracking, scaling, peeling or swelling. Usually itching or pain is associated with the rash. The general term for a skin rash is dermatitis, meaning inflammation of the dermis, one of the layers of the skin.
Causes:
There are several possible causes for a rash. These can be placed into various categories:
Irritant contact dermatitis
This is the most common type of contact dermatitis, involves inflammation resulting from contact with acids, alkaline materials such as soaps and detergents, solvents, or other chemicals. The reaction usually resembles a burn. The damage can cause discomfort ranging from mild irritation to severe pain.
Allergic contact dermatitis
Allergic contact dermatitis, the second most common type of contact dermatitis, is caused by exposure to a substance or material to which one has become extra sensitive or allergic. The allergic reaction is often delayed, with the rash appearing 24 – 48 hours after exposure. The skin inflammation varies from mild irritation and redness to open sores, depending on the type of irritant, the body part affected and sensitivity. Allergic contact dermatitis may involve a reaction to a substance that the patient is exposed to, or uses repeatedly. Although there may be no initial reaction, regular use (for example, contact with metals e.g. nickel) can eventually cause sensitivity and reaction to the product.
Some products cause a reaction only when are in contact with the skin and are exposed to sunlight (photosensitivity). These include sunscreens, sulpha ointments, some perfumes, coal tar products and oil from the skin of a lime. A few airborne allergens, such as pollens or insecticide spray, can cause contact dermatitis.
Atopic dermatitis
Atopic dermatitis also referred to as atopic eczema is due to a hypersensitivity reaction (similar to an allergy) in the skin, which leads to long-term inflammation of the skin. Eczema is most common in infants. Many people outgrow it by early adulthood. The condition tends to run in families. People with eczema often have asthma or hay fever too. There is often a family history of allergic conditions such as asthma, hay fever or eczema. A child with atopic dermatitis has red, chapped cheeks, with scaling patches on the arms, legs, body and scalp. It seems to worsen in winter and improve in summer. This is because cold dry air aggravates the condition. The skin is inflamed with a lot of itching.
Seborrheic dermatitis
Seborrheic dermatitis is a common, inflammatory skin condition that causes flaky, white to yellowish scales to form on oily areas such as the scalp or inside the ear. It can occur with or without reddened skin. Cradle cap is the term used when seborrheic dermatitis affects the scalp of infants. Seborrheic dermatitis is thought to be due to a combination of an over production of skin oil and irritation from a yeast called malessizia. You can treat flaking and dryness with over-the-counter dandruff or medicated shampoos containing salicylic acid, coal tar, zinc, resorcin, ketoconazole, or selenium.
Medication –induced dermatitis
Penicillin is the most common medicine that can cause a rash. Others include sulpha-containing drugs, anticonvulsants, insulin preparations (particularly animal sources of insulin), iodinated (containing iodine) x-ray contrast dyes or aspirin. The prescriber should be notified about the reaction be before the medication is discontinued.
Specific causes of rash in children.
There are some specific causes of dermatitis that the pharmacist may be able to recognize. Some are typical of allergic contact dermatitis, while others are caused by irritants.
Nappy rash or diaper rash. By far the most common skin problem in infants is nappy rash. Changes in the skin pH under nappies allow faecal enzymes in faeces to damage the skin. If the skin is broken, a physician should be consulted to assess possible bacterial/fungal infection. Prevention consists of removing urine and faeces from the skin as quickly as possible and applying barrier ointments with protective properties (i.e. petrolatum). Yeast nappy rash is caused by a type of yeast called candida, which also causes thrush in the mouth. The rash looks different from a regular diaper rash. It is very red, and there are usually small red bumps on the outer edges of the rash. This rash requires treatment with anti-fungal medication.
Heat rash or prickly heat is caused by the blockage of the pores that lead to the sweat glands. It is most common in very young children but can occur at any age, particularly in hot and humid weather. An infant does not sweat. The sweat is held within the skin and forms little red bumps or occasionally small blisters.
Erythema toxicum can cause flat red splotches (usually with a white, pimple-like bump in the middle) that appear in up to half of all babies. This rash rarely appears after five days of age, is usually gone in 7 – 14 days, and is nothing to worry about.
Baby acne is caused by exposure to the mother’s hormones. Red bumps, sometimes with white dots in the center, may be seen on a newborn’s face. Acne usually occurs between two and- four weeks of age, but may appear up to four months after birth and can last for 12 – 18 months.
Cradle cap (seborrheic dermatitis) causes greasy, scaling, crusty patches on the scalp that appear in a baby’s first three months. It usually goes away by itself, but some cases may require treatment with medication.
Hives are red welts that appear to move around on the body. For example, if you drew a circle to mark one of the welts, a few hours later that circle would not have a welt in it, but there would be welts on other parts of the body. They differ in size and shape. Hives may last for a few weeks. The cause is uncertain.
Insect induced rash: Insect bites and stings can cause immediate skin reactions. The bite from fire ants and the sting from bees, wasps, and hornets are usually painful. Bites caused by mosquitoes, fleas and mites are more likely to cause itching than pain in a single area where the insect has bitten. Tick bites and scabies produce a rash.
Treatment guidelines for dermatitis
When the rash is self-treatable, the pharmacist can make recommendations depending on the cause of the rash.
Protectants: Skin protectants relieve minor irritation and itching by providing a mechanical barrier against harmful or annoying stimuli. They include aqueous cream, petrolatum (e.g. Vaseline®) and colloidal oatmeal.
Local anaesthetics: These anaesthetize pain/itch receptors to relieve rash discomfort. They are found in such products as Amethocaine® cream or Calathestic Cream® (benzocaine, calamine, phenol and pheniramine)
Antihistamines: Topical antihistamines also produce a degree of local anaesthesia and reduce the itch e.g. Mepyramine (e.g. Anthisan® or Allergex Mepyramine® cream)
Counterirritants: Camphor, menthol, and methyl salicylate also relieve the pain and itch of rashes. e.g. Germolene® or Antipeol®
Hydrocortisone: Topical one per cent hydrocortisone creams or ointments relieve itch and inflammation of rashes. Products include Mylocort® or Stopitch®.
Antiseptics and antifungal creams: If the rash is infected, antibacterial products e.g. Bactroban® or Betadine® will effectively relieve the infection. Fungal infections as often seen in nappy rash can be treated with topical antifungal products e.g. clotrimazol creams.
Conclusion
Rash in infants and children is a concern for the carers but can often be treated with over the counter products on advice from the pharmacist. Patients should be referred if dermatitis persists for more than seven days, if it appears to clear up and then worsens, covers a large portion of the body, causes severe itching, or is in a location difficult to care for (e.g., around the eye, conjunctiva, inner nostrils, ear canal, vagina). Patients with hives should be referred if the hives are an unusual colour, bruised, blistered, or do not itch.
Marjolein Bench BPharm IMM
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