I wonder if some of the info in these links would help? Could it be related to brand?
Determination of patulin in apple juice by liquid chromatography | Journal of AOAC International | Find Articles at BNET
PATULIN IN APPLE JUICE.(Brief Article) | Article from The Food Institute Report | HighBeam Research
Clear or Cloudy - Choosing Which Apple Juice Is Best for Good Health
What do we know about allergies and fruit juice? Most commercially available fruit juices are manufactured with aseptic heat packaging, a process through which most allergens will be denaturated, except for lipid transfer protein, which occur in apples and other fruit. Thus, an allergy is unlikely. What about intolerance? Apple juice has one of the highest fructose contents among fruit juices and can cause gastro-intestinal (GI) symptoms such as flatulence and diarrhoea, especially in young children, due to malabsorption of fructose. Malabsorption has been found in children with intakes of as little as 15ml fruit juice/kg body weight. So, a case of fructose intolerance?
When fructose was excluded from the diet and lactose reintroduced, the diarrhoea disappeared immediately. Fructose intolerance was diagnosed, and it was then left up to the mother to determine what level of fructose (in diluted form) her son could tolerate.
Allergy Advisor - Allergy and Intolerance Newsletter
The acidity of apple juice may result in bronchoconstriction in some individuals. (Santucci 1990 ref.1121 8)
Patients who are birch pollen- and apple-allergic improve if desensitised to birch pollen. (Herrmann 1995 ref.1132 8)
Apple is considered a common cause of gastrointestinal allergy and aphthous stomatitis.
AllergyNet - Allergy Advisor Find
How can my daughter be allergic to applejuice but not apples? - Yahoo! Answers
And so forth.
I did not know that anyone would be allergic to apples; but then I am allergic to peanuts; really hate those things.