Atopic or allergic diseases (atopy is just another word for allergy) have been increasing all over the world for the last 30 years. It is not unexpected then that allergic rashes, or atopic dermatitis (AD), has also been increasing.
The reasons for this are not well understood, and genes are involved, but the change has occurred too fast for it to be genetic alone. The environment in which we now live—changes in diet during pregnancy and infancy, including the move away from traditional foods into ultra-processed foods, the dramatic increase in Caesarean sections from five to 40 per cent in some areas, which alters the baby’s gut microbiome and predisposes to allergic conditions, and the decrease in breastfeeding certainly has something to do with it.
All of this is worsened by the modern idea that “germs” are always bad and that we should try to live in a “germ-free” environment, as sterile as possible, as if that is possible. As if we humans do not have extremely powerful defence mechanisms that protect us, if we give them a chance by living a life filled with song and dance and friendship, good food and plenty of green outdoor activity.
However, if there is one major thing parents who suffer from allergic conditions, whether they are skin-related, food-related, or respiratory-related, can do to help prevent their children from suffering from any allergic condition, it is to exclusively breastfeed from birth to six months.
Atopic dermatitis has increased by 20 per cent since the early 1990s. The prevalence of AD is high, affecting up to 20 per cent of children and up to 10 per cent of adults, so it is more common in children.
It becomes apparent in early childhood, with most patients experiencing the onset of the disease before the age of five years. Children do tend to grow out of it. As they do, many develop other forms of allergic disease, firstly food allergies and then allergic rhinitis and bronchial asthma. This association of different allergic diseases with different ages is known as the “atopic march”. Atopy comes from the Greek “atopos”, meaning “without place”, which hints at this frequent occurrence of disease in various sites of the body.
Atopic dermatitis is a common, chronic, non-communicable skin disease characterised by dry skin, localised red scaly patches and intense itching. The itching causes scratching, and scratching causes more skin damage and more skin lesions, which causes more itching. This is the itch-scratch-itch cycle. The itch must be neutralised before the rash can improve.
The rash occurs on and off. It is triggered by many things: junk food, stress, irritants, allergens, infections, and changes in weather or season. It’s is triggered by many things. These triggers can cause acute flare-ups. A child can go from being happy and carefree to a sickly, scratchy, hyperactive child within days.
AD is often accompanied by sleep disturbances, anxiety and depression in older children. A baby or child with severe AD itching is a miserable baby, child and mother.
Atopic dermatitis has a typical age-related distribution. In infants, the face, scalp, cheeks (DIAGRAM 1), and the sides of the arms and legs or back of the elbows or knees are frequently involved, but the whole body may be affected in severe cases. As the child grows, the folds and creases of the body, around the neck, the wrists and ankles and especially the inner elbow creases (DIAGRAM 2) or the back of the knees typically become more involved.
What causes AD is not well understood.
As usual, genes are involved, and now that I have records of grandparents with AD who came to see me 40 and 50 years ago as children, and then their children twenty and thirty years ago, and now their grandchildren, it is easy to see the family links.
It is surprising how quickly people forget why they go to the doctor. Almost no one remembers the repeated visits for allergic conditions like AD, allergic rhinitis and bronchial asthma, the three most common allergic diseases which form the atopy triad.
AD is very common in Trinidad and Tobago. When I first came to T&T in 1978, Dr Michael Camps, one of the first Trinidadian paediatricians, told me he was seeing an average of two to three cases a week, and I was surprised. It was common but not that common in Venezuela and Baltimore.
Over the years, I have come to agree. It is common. The mildest cases simply overreact to mosquito bites and are easily treatable, but the worst are frustrating.
The basis of treatment is prevention, as in breastfeeding and food from the land and not from bottles. The skin must be kept exposed, well-creamed, and soft until the child grows older. Powerful medications, topical and oral, are available for effective treatment.
