I first observed this type of "seasonal disintegration" in my early work with Adam. When he was a very young boy, he was so generally disorganized (in his language, sensations and interaction with others), that any changes in behaviour and reactivity during certain seasons of the year were not noticeable. That changed as he began to learn to communicate and interact with the larger world. Suddenly, without any apparent warning, he seemed to go backwards in his skills. He was hand-flapping and toe-walking, going back and forth in front of the heater grid lost in the visual pattern, unable to use or understand words that he had been learning - he retreated entirely into his own world again. Understandably, all of the adults around him were very distressed, and we began to frantically change up his program, trying to bring back his earlier success. In a couple of months, he did seem to be back on track, and we moved on. But it kept recurring - every once in a while, he would apparently lose all of his hard-won skills.
At the same time, I was trying to unravel the more traditional allergy symptoms of my oldest son. A friend asked me to accompany her to a talk given by Dr. Doris Rapp, an allergy specialist who had expanded her traditional training to explore more unusual allergic responses and potential treatments. The talk was a revelation. She not only described the symptoms that my son had been experiencing since he was a baby, she also showed us videos of children who were showing the same types of temporary disintegration of mental and language abilities that we had been observing in Adam. I looked back through my notes, and discovered that Adam's "disintegrations" matched the same timeline as my eldest son's difficulty with congestion and breathing - and both patterns matched the population of people who are allergic to molds and mildew.
Over all the years since then, we have seasonally adjusted Adam's program each spring, and to a lesser extent in the fall. As he has gotten older, Adam himself is more aware of the days when he is suffering from his allergies. Here is a sequence of pictures that he drew this past fall on the topic, on a day that he was definitely not feeling well (this is the picture he is drawing in the photograph on the home page of our website):