Seasonal allergy and seasonal decrements in athletic performance

Food-dependent exercise-induced anaphylaxis in childhood

The clinical syndrome of food-dependent exercise-induced anaphylaxis (FDEIA) is typified by the onset of anaphylaxis during (or soon after) exercise which was preceded by the ingestion of the causal food allergen/s. In FDEIA, both the food allergen/s and exercise are independently tolerated. FDEIA is an uncommon allergic condition in childhood, but nonetheless is an important differential diagnosis to be considered when faced by a child who has experienced exercise-associated anaphylaxis. The diagnosis of FDEIA is heavily dependent on the clinical history. Allergy tests may need to be performed to a broad panel of food and food additives. Modified exercise challenges (performed with and without prior ingestion of food) are frequently required as allergy test results frequently return low-positive results. A diagnosis of FDEIA facilitates the safe independent return to exercise and reintroduction of foods for patients who otherwise may unnecessarily avoid exercise and/or restrict their diet. The natural history of FDEIA is unknown; however, a safe return is usually achieved when the ingestion of the causal food allergen/s and exercise are separated.

Mood-worsening with high-pollen-counts and seasonality: a preliminary report

BACKGROUND

Because aeroallergens produce inflammation in the respiratory airways, and inflammation triggers depression in vulnerable individuals, we hypothesized that mood sensitivity to pollen, the most seasonal aeroallergen, will be associated with a greater seasonality of mood. Since pollen is absent during winter, we specifically predicted that mood sensitivity to tree pollen will predict non-winter SAD but not winter SAD.

METHODS

A convenience sample of African and African American college students who lived in the Washington DC metropolitan area for at least the past 3 years completed the Seasonal Pattern Assessment Questionnaire (SPAQ), from which the Global Seasonality Score (GSS) was calculated, a diagnosis of cumulative SAD (syndromal or subsyndromal SAD) was derived, a seasonal pattern (winter vs non-winter) identified, and self-reported mood changes during high pollen counts obtained. A Mann-Whitney test was used to compare GSS between participants with vs without mood worsening during high pollen counts. The capability of mood worsening with high pollen counts, gender, ethnicity, and age to predict non-winter SAD was analyzed with logistic regressions.

RESULTS

GSS was greater (z=5.232, p<0.001) in those who reported mood worsening with high pollen counts. Mood sensitivity to pollen predicted non-winter SAD (p=0.017), but not winter SAD.

LIMITATIONS

The SPAQ is not a definitive tool to assess seasonality, and self-reported mood worsening with high pollen counts relies on recollection. No direct measures of depression scores or pollen counts were collected. The non-winter SAD concept has not been previously established.

CONCLUSIONS

Our study, which should be considered preliminary in light of its limitations, suggests that self-reported mood-worsening with high pollen count is associated with a greater seasonality of mood, and predicts SAD of non-winter type.

Seasonal rhythms and exercise

Levels of leisure-time physical activity and physical fitness are generally higher in the summer than in the winter months for most people living away from the equator. The notion that an abrupt increase in physical activity in the spring, after a period of relative inactivity, can trigger sudden cardiac events has not been confirmed. There are seasonal variations in the physiological responses to exercise and the occurrence of injuries during participation in sports, but it is not known whether these changes are explained by fluctuations in activity levels and environmental conditions, or by any endogenous circannual rhythms in the human. There are indications of endogenous control for some physiological processes (eg, the metabolic responses to a given intensity of exercise) that seem to mediate more favorable effects of exercise on body composition in the winter. Well-trained athletes show obvious seasonality in their competitive performances, generally in line with adopted annual periodization strategies, although these strategies can be disrupted by external seasonal factors, such as heat stress or the susceptibility to upper respiratory tract infections. Maximal oxygen consumption and other physiological indicators of exercise performance might not mirror seasonal variation in real performances, which suggests that top-class athletes maintain a good level of general physical conditioning throughout the year.