Histamine

Pronunciation: (HISS-tuh-meen).

Generic name: Histamine
Brand names: Histamine Phosphate, Histatrol, Histamine Positive Skin Test Control
Drug class: Diagnostic Agent (positive skin-test control); Histamine Receptor Agonist

Availability and supply rules vary by country

Trade names by country: United States · Canada

What Histamine is and how it works

Uses, formulations, monitoring, and supply rules can differ by patient, product, and country. Follow the exact local product information and professional advice.

Mechanism of action: how Histamine works

Histamine acts as an agonist at histamine receptors (H1, H2, H3, and H4). In diagnostic skin-test use, it primarily stimulates H1 receptors in the skin, causing vasodilation, increased vascular permeability, and the classic wheal-and-flare response used as the positive control. Historically, its H2-receptor-mediated stimulation of gastric parietal cells was used to measure gastric acid secretion, but this diagnostic use is no longer part of current FDA labeling. (2)

What Histamine is used for

Positive control in allergy skin testing (percutaneous/prick or intradermal, Type I hypersensitivity testing)

This is the only current FDA-labeled use: histamine confirms that a patient's skin can mount a normal wheal-and-flare reaction, so a negative allergen test result can be trusted rather than mistaken for a false negative. (2)

NOT a current approved use: pheochromocytoma diagnosis

Historically histamine was used as a provocative test for pheochromocytoma. Current FDA labeling explicitly states this product is 'not intended for diagnosing pheochromocytoma' because of the risk of severe hypertensive crisis; this use has been abandoned in favor of safer biochemical tests. (2)

NOT a current approved use: gastric acid secretion testing

Historically histamine was used to stimulate and measure gastric acid output. Current FDA labeling explicitly states this product is 'not intended for ... testing gastric acid secretion'; pentagastrin and other methods replaced it. (2)

Before taking Histamine

Do not take / not appropriate for

Contraindicated in patients with a history of severe allergic reactions, uncontrolled asthma, active peptic ulcer, or severe cardiovascular disease. (Contraindication) (2)
Emergency resuscitation equipment should be available during administration. (Contraindication) (2)

Tell your clinician about

(2)

How to take Histamine

General Instructions: Histamine is administered only by a healthcare professional, as a positive control alongside allergen skin testing. Two approved routes exist: percutaneous (prick/scratch) testing using histamine base 1 mg/mL applied to the skin, or intradermal testing using a more dilute 0.1 mg/mL solution. The FDA label explicitly states this product is not intended for subcutaneous injection or inhalation.. Adult Dosing: For intradermal testing, 0.01-0.02 mL of the 0.1 mg/mL solution is injected intradermally; for percutaneous testing, 1 mg/mL solution is applied and the skin is pricked or scratched through the drop. Results are read at 15 minutes.. Pediatric Dosing: The same skin-testing routes are used in infants and children; about 20% of infants under six months may show a false-negative (no) reaction, and skin reactivity increases with age up to about age six. Testing should only be performed by experienced clinicians.. Administration: Administered onto or into the skin by a trained healthcare provider, alongside the allergen panel, using separate sterile equipment for each patient. Do not self-administer.. When To Stop: Administration is a one-time procedure per testing session. If any severe systemic reaction occurs, the procedure should be stopped immediately and treated as an emergency.. Storage: Store refrigerated at 2-8 degC (36-46 degF), protected from light. Do not store at room temperature. Keep out of reach of children.
This page does not provide a dose calculator. Dosing must follow the prescriber, pharmacist, or product label.

(2)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (2)

Missed dose

Histamine is given as a single dose for diagnostic purposes. If a dose is missed, contact your healthcare provider to reschedule the test.

Overdose

Excess histamine exposure during testing may cause severe headache, a rapid drop in blood pressure, flushing, and bronchial constriction; the FDA label warns this can progress to vasomotor collapse, shock, and even death in rare cases. Because histamine is administered only in a clinical setting by a healthcare professional, true patient-directed overdose does not apply — seek emergency medical attention promptly if a severe reaction occurs during or after testing. Clinician-directed treatment includes epinephrine and antihistamines, with supportive airway management as needed. (2)

Side effects

Side effects and their urgency vary; report severe, persistent, or concerning symptoms to a healthcare professional.