However, in sharp contrast to the 2- to 3-fold increase in IgE antibodies to timothy seen after the timothy grass pollen season in timothy allergic individuals, one third of the recommended daily dose of PHO taken during 1 week resulted in a close to 100-fold increase in serum levels of IgE antibodies to PHO and QAI within 3 weeks and equally so of IgE in all of the 13 sensitized patients exposed [9,11]. Here, IGHE is linked to primary hypertrophic osteoarthropathy.