Cross-reactivity with latex (Niggemann et al. 2002) 
Immunoblot inhibition results indicated a 16 kDa allergen as the cross-reactive protein between birch pollen, celery and lychee (Fah et al. 1995) 
Wellhausen et al. 1996  and Vieths et al. 1998  identified an IgE-binding 35-kDa protein from birch pollen (Bet v 5) with cross-reacting homologs in various plant foods, including lychee.