Delayed-type Hypersensitivity Treatment & Management

Updated: Sep 26, 2018
  • Author: Harumi Jyonouchi, MD; Chief Editor: Russell W Steele, MD  more...
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Medical Care

Delayed-type hypersensitivity (DTH) skin testing requires the use of Ag doses as defined under Lab Studies. See Lab Studies for a more complete discussion of the interpretation of DTH reactions.

DTH responses represent cellular immune responses to recall Ags to which the subject has been exposed at least 4-6 weeks previously. The reaction occurs 48-72 hours after exposure and induces induration of 5 mm or more.

The inflammatory reaction may be sufficient to induce pain at the local site. Topical steroids and diphenhydramine have been used to decrease an unusually severe local reaction. If an excessive reaction is anticipated, such as in caseating tuberculosis, decrease the amount of Ag; for M tuberculosis, for example, decrease the strength of the PPD from the customary 5 units to 1 unit.

Negative reactions to a recall Ag to which the patient is known to have adequate exposure require investigation for an underlying illness or a T-cell immunodeficiency.

Positive DTH reactions do not indicate protection against the recall Ag that is tested. Antibody responses to the specific antigen usually reveal better correlation with immune protection.

In patients with mutations in the IFN)-γ/IL-12/IL-23 signaling pathways, medical care includes consideration of hematopoietic stem cell transplantation (HSCT) in patients with severe deficiencies and exogenous IFN-γ therapy in patients with partial deficiencies with milder clinical features. In the presence of NTM infection, patients require treatment with an aggressive regimen of anti-mycobacterial drugs. HSCT may not be successful in the presence of systemic, progressive NTM infection.



In a context in which a T-cell disorder is likely, a clinical immunologist should manage the diagnostic workup in order to obtain informative cell-mediated immunologic testing and appropriate mutational analysis.

Both types of evaluations for rare T-cell disorders are commonly available only in laboratories of specific investigators. However, intracellular cytokine staining of IL-17 and mutational analysis of genes associated with deficiencies of IFN-γ and IL-12 pathways can be attainable in the commercial laboratories.



Resolution of protein-energy malnutrition in immunocompetent hosts induces an intact DTH response.