Atopy – without a place
The word Atopy originated in 1923 when two doctors – Dr Cooke and Dr Coca were classifying and categorising different rashes and skin conditions. The doctors had a group of patients who did not fit into Dr Coca’s classification system so they made up the word atopy to categorize the group. Atopy means ‘without a place.’
The group of patients put into the Atopy group all had sensitive skin and were susceptible to irritation and eczema. Most of them had family members with asthma, hayfever or allergies. Today the word Atopy is used to refer to an inherited allergic condition.
The reason atopic people have sensitive skin is not known. However most atopic people will develop eczema at an early age, usually before 2 years old, but rarely before 2 months old.
It is not the eczema that is inherited but rather the atopy. If a child has one atopic parent (ie having eczema, asthma, hayfever or allergies) there is a 20% chance the child will be atopic as well. If both parents are atopic the chances of the child being atopic rise to 60%.
Being atopic does not give you eczema. It simply makes you susceptible to develop the condition. The skin must be irritated by something for the eczema to develop. We know these irritations as eczema triggers.
Atopic skin is different
Atopic skin does not function the same as normal skin. It does not have the ability to act as an effective barrier keeping water in and irritants out. Water evaporates easily leaving atopic skin very dry.
Atopic people are also more perceptive to the sensation of itch. A mild irritation to the skin that would normally be perceived as a gentle tickle or simply the sensation of touch will be perceived by the atopic skin as the sensation to itch. Hence atopic skin is typically very dry and itchy.
Skin sensitivity and skin barrier tend to improve over time with 50% of atopic children being less susceptible to skin irritation by the age of 5 years and 90% less susceptible by the age of 9 years. Eczema may reappear in adulthood but usually not before the age of 60.
Why do atopic people get eczema?
It is believed that the excessive itching of the atopic person leads to the rash of eczema developing. However it is not just the itching that will lead to the skin irritation. The protective skin barrier is not working properly so normal elements will irritate the skin resulting in eczema. Soaps, cleaners, rough woolen clothing or frequent bathing may all irritate atopic skin triggering eczema.
After Atopic features
Atopic people tend to have other lesser-known seemingly unrelated characteristics. They will often have a small crease on the lower eyelid, near the nose or dark circles under the eyes. Small acne-like bumps may be present on the back of the arms.
Atopic skin is more prone to the wart virus or fungal growths like ringworm or athletes foot. These characteristics will be helpful in the diagnosis of an atopic person even if eczema or skin irritation is not present.