Indications for inhalation challenge

Indications

for inhalation

challenge

Richard R. Rosenthal, M.D., Chairman, Hyman Chai, M.D., David A. Mathison, M.D., Sheldon L. Spector, M.D., and Robert G. Townley, M.D. Study Group on Indications, Bronc,ho~pro~oc~ution Committee,

American

Academy

The ability to identify and characterize the asthmatic state cannot help but prove a useful tool in the clinic and research laboratory, but as with any procedure, it is difficult to envision or anticipate every exigency for which inhalation challenge will be appropriate. As our understanding of the immune response of the lung unfolds, and as we accumulate data relating hyperactive or responsive bronchi as a risk factor for the development of yet unrecognized pulmonary disease or for occupational lung disease, the indications for inhalation challenge may expand or contract and new caveats may emerge. Undoubtedly, the large spectrum of research projects from physiology to epidemiology which incorporate bronchoprovocation will be continued. It is neither possible, nor even appropriate to comment upon the propriety of inhalation challenge for all such protocols. This will be the responsibility of the individual investigators and their institutional review boards. Instead, the indications for antigen and cholinergic or histamine inhalation challenge listed in Table 1 are meant to reflect the present state of the art and are oriented toward the practice of clinical medicine. It is intended that as the use of inhalation challenge in pulmonary medicine and allergy grows, these guidelines will help add perspective to the role and utility of these techniques.

oj’ Allergy

TABLE I. Clinical challenge

indications

for inhalation

Antigen

1. Clarification of the role of specific allergens in asthma, especially when other diagnostic criteria are inadequate. It should be recognized that a false positive reaction is possible; that is, allergic patients may have bronchoreactivity to antigens that are clinically unrelated to their asthma. Conversely, antigen challenge may be useful to clarify the nonrelevance of cutaneous or serum tests when the history is equivocal. Provocation with antigen should have some clinical relevance, such as contingency of intervention by immunotherapy or specific avoidance. 2. To define, when appropriate, the natural history of antigen sensitivity when there is no immunologic intervention, or conversely, for evaluation of the therapeutic effect of immunotherapy. 3. For the evaluation of new or unrecognized allergens or provocative agents in pulmonary disease, such as for the assessment of occupational inhalants in susceptible patients. Methacholine, carhachol, or histamine I. To identify the patient with hyperactive airways. regardless of cause, as well as to measure the extent of such hyperactivity when appropriate.

Reprint requeststo: Richard R. Rosenthal, M.D., The JohnsHopkins School of Medicine at Good SamaritanHospital, 5601 Loch Raven Blvd., Baltimore, MD 21239.

OOSl-6749/79/130603+01$00.10/0

@I 1979 The C. V. Mosby

Co.

Vol. 64, No. 6, Part 2, p. 603