Seasonal Variation in the Phagocytic Activity and Arachidonic-Acid Metabolism of Human Blood Monocytes in Healthy Non-Smokers, Smokers and Chronic Bronchitics

Seasonal variation of dermatologic disease in the USA: a study of office visits from 1990 to 1998

“…16 Human immune function exhibits seasonal variation, 17 including seasonal differences in B and T cells 18 and phagocyte function. 19 Pineal melatonin, which codes day length information and is believed to influence human immunity, is secreted more vigorously in darkness and suppressed in sunlight. 20 The observation that office visits for actinic keratoses showed strong seasonal variation is not surprising.…”