allergies / nasal irritation / sneezing in sunlight?

Investigate deficiency in B-vitamins.

calcium, magnesium and zinc deficiency; which contributes to elevated histamine levels. Zinc is a key factor in how your body stores histamine.
– Source?

Investigate Copper toxicity, as it will antagonize zinc, reducing immune function.

Investigate depressed Cortisol, which is a powerful suppressor of inflammation.