Clues to an Occupational Allergic Reaction

 

Features:

(1) "Monday fever"

(2) gradual decrease in symptoms throughout the work week

(3) clinically well over the weekends or when on vacation (away from the workplace)

(4) unexplained low grade leukocytosis that normalizes on removal from the workplace

 

"Monday fever" refers to occurrence of fever on the first day of return to work, associated with a waning of tolerance over the weekend. Other symptoms may similarly be most marked on Mondays or the first day of return to work.

 

Differential diagnosis:

(1) toxic building syndrome due to dust or molds, with respiratory symptoms occurring during working hours but reduced symptoms in off hours

(2) myelodysplasia secondary to chemical exposure

(3) Legionnaire's disease