What to do if you have contact dermatitis

Contact dermatitis (or commonly known as eczema) is a particularly important consideration in people with skin disease. Skin disease means that there are more likely to be breaks in the skin, and an individual is at higher risk of developing an allergic contact sensitization as the allergen can easily penetrate the skin’s protective layer. Also, atopic individuals (those with underlying atopic eczema) are 13.5 times more likely to develop contact dermatitis than those without atopic eczema. Clear distinctions needs to be made between the different mechanisms that cause contact dermatitis. 

What happens during allergic reactions?

Allergic reactions involve an immunological response to contact with an external substance. A type I reaction is immediate; histamine is released, causing hives, rhinoconjunctivitis (streaming eyes) and, more seriously, angioedema and anaphylaxis. The reaction can last for up to two hours and can be clearly life threatening. A type IV reaction, which more common, involves the body becoming sensitized to a substance (antigen) over a period of time. The substance penetrates the skin barrier where the Langerhans cells attach to the antigen and present it to the T lymphocyte helper cells. These are then expanded in the lymph node so that T-effector and T-memory cells are released into the bloodstream. This process of sensitization can take between 5 and 21 days. Following this first exposure there is no outward reaction, but on subsequent exposure the sensitized T cells migrate to the point of contact, causing inflammation. This normally takes 48-72 hours. An allergic reaction may cause an overall rash rather than one just at the point of contact. 

What to do if you have irritant reaction?

An irritant reaction is a non-immunological reaction that occurs when a substance comes into contact with the skin. An acute reaction occurs immediately following contact with substance such as acids and alkalis, whereas more cumulative effects occur following prolonged contact with such things as soaps and solvents.

It can be difficult to distinguish between allergic and irritant dermatitis, and indeed difficult to ascertain exactly what is causing the dermatitis. Patch testing is a way of determining what is causing contact dermatitis, although this usually needs to be done within a dermatology department. It involves taking an in-depth history to gain a picture of the sorts of things someone may be reacting to. Then number of chemicals commonly found in everyday substances, alongside substances related to an individual’s occupation, are placed in small metal chambers and stuck onto the back (Plates 1 and 2). The concentrations and quantities are such that irritant reactions should be kept to a minimum, but these can still occur. Readings are taken 48 hours and then at 72+ hours, the time lapse allowing the allergic reaction to occur. This is why, when trying out a new cream or ointment on a patient, a small patch test should be performed and left for 48 hours to be sure that an allergic reaction is not going to take place.

Patients with chronic leg ulcers are particularly at risk of developing allergic reaction When the skin barrier function is breached, there is a particular risk of absorbing allergens from dressings and topical applications. A study showed that 23 per cent of leg ulcer patients were allergic to wool alcohols found in lanolin, but more recent work has shown that modern techniques have allowed lanolin to be “purified” to the extent where it has virtually no allergenic properties. However, there is still concern about the use of cream emollients for patients with leg ulcers, as their preservatives can act as allergens. Using ointment-based lotion emollients for patients with leg ulcers is always safest. 

Although patch testing is a very useful way of identifying substances that might be causing contact dermatitis it is not infallible, as placing a small amounts of chemical on the back of individuals does not create the environment they find themselves in at work. However, it positives are found then advice must be given about avoiding this substance. This can be particularly difficult if the substance is a very common one like latex. 

Is latex the culprit why I have contact dermatitis? 

Latex allergy is becoming more common, and is real problem for many nurses. For some, the allergy is caused by the leaching out of chemicals that are used during the manufacture of the gloves. This is likely to lead to Type IV reactions of contact dermatitis. A type I allergy is likely to occur in someone who has allergy to latex itself, and for these people the only solution is to wear latex-free gloves. It is worth noting that some brands of glove claim to be hypoallergenic, which means they contain lower amounts of chemicals from manufacture, but they are not latex-free. Some patients are allergic to latex and will react when touched by a latex glove, and normally these people will carry a warning card. However, it is becoming more common practice for health care workers to avoid latex gloves altogether. 

How do you protect yourself from contact dermatitis?

When it is possible for an individual to avoid the substance that causes the contact dermatitis (e.g., car mechanic who is sensitized to oil), other strategies must be employed. These involve wearing protective gloves, careful washing of hands, and wearing barrier creams or ointments. It can be very distressing for patients to find that is their job that is causing the skin problem, especially if an acute allergy means that the only option is to give up the job. However, it can also be a major relief to find the cause of what is some cases amounts to years of suffering. For most people, discussion with the occupational health department in their workplace and careful skin care can lead to a solution that allows the individual to carry on working.