Allergic conjuctivitis caused by sugi (Cryptomeria japonica D. Don) pollen out of season

Allergic conjunctivitis caused by sugi pollen is considered to be strictly a 'spring disease'. However, a recent report indicated that sugi pollen is scattered not only in spring but in all seasons, especially in the autumn. We retrospectively determined the number of patients with allergic conjunctivitis caused by sugi pollen during each month for 3 consecutive years, and also investigated the growth of sugi male cones in November for four years. Diagnosis of allergic conjunctivitis was based on symptomatic complaints, clinical findings, and serum sugi pollen specific IgE measured by the Multiple Antigen Simultaneous Test 16. The annual incidence of allergic conjunctivitis peaked twice, once in spring and again in autumn. Scattering of sugi pollen occurred mostly in March and October, whilst the growth of sugi male cones was highest in November. Thus, allergy to sugi pollen can cause allergic conjunctivitis both in the spring and late autumn.