If negative Phadiatop and fx5 results are obtained, the tested individual is not atopic. If the suspicion of allergy remains, total IgE could be measured to confirm the suspicion. An increased total IgE value indicates that it might be worth looking for more uncommon allergens (pets, occupational allergens etc.) If relevant, it could also be worth checking for parasites, as IgE plays a major beneficial role in the defense against parasitic worms.