Thank you for your recent inquiry.
Respiratory allergy to bat droppings (guano) has been well documented in the literature (see abstracts copied below).Exposure in patients sensitive to guano can produce both rhinitis and asthma.
It is possible, but I could not find any documentation, that guano could act as a nonspecific irritant as well, thus worsening rhinitis in patients with nonallergic rhinitis. However, as noted, I could find no information in this regard.
Thank you again for your inquiry and we hope this response is helpful to you.
Lancet. 1987 Feb 7;1(8528):316-8.
Respiratory allergy to inhaled bat guano.
el-Ansary EH, Tee RD, Gordon DJ, Taylor AJ.
In the Sudan many asthmatic patients attribute their symptoms to inhalation of bat droppings. Design of the roofs of many Sudanese buildings allows black bats to roost; guano drops through cracks in the ceiling into the rooms below where it can be inhaled and cause allergic respiratory disorders. Seven atopic patients seen at Sennar Hospital with bat-related case-histories were investigated. Six had bronchial asthma and allergic rhinitis and one had asthma alone. Extracts of yellow hairy bat, black bat, and bat droppings were made. All seven patients had a positive skin prick test and specific IgE antibodies (RAST) to bat droppings. Three patients also had a positive RAST to both yellow and black bats and one patient to yellow bat. Droppings are probably the major allergen source in bat-related respiratory allergy
J Investig Allergol Clin Immunol. 1998 Nov-Dec;8(6):365-9.
Bat feces as an indoor allergen.
Alonso A, Irañeta SG, Rodríguez SM, Scavini LM, Rodríguez SR.
Allergy Center, Hospital de Clínicas, Buenos Aires, Argentina.
We have demonstrated in an animal model (specific IgG) as well as in atopic patients suffering from rhinitis/asthma (specific IgE) that bat feces have antigenic properties. A single peak with high glycoprotein content was obtained by chromatography, while SDS-PAGE revealed several proteins between 29 and 116 kDa which showed immune serum blotting at 43.6 and 66 kDa. Positive specific skin tests with bat feces and IgE-RAST anti-bat feces were detected in atopic patients living in tall buildings and old houses in Buenos Aires. As bat feces did not cross-react with bat epithelium, studies evaluating rat serum and epithelium and pigeon feces in order to analyze the role of bat serum proteins, such as IgA, are encouraged
Phil Lieberman, M.D.