What are the allergic symptoms of a tuberculosis skin test?

The allergic symptoms of a tuberculosis skin test are diverse, primarily including local and systemic reactions. Local reactions may involve skin redness, itching, rash, swelling, and in more severe cases, induration or blistering necrosis. These symptoms typically appear within 48 to 72 hours after the skin test and may be accompanied by local reactions such as lymphadenitis and lymphangitis. Systemic reactions can be more severe and may include difficulty breathing, palpitations, chest tightness, and anaphylactic shock. Among these, anaphylactic shock is the most severe allergic reaction and can be life-threatening, although its occurrence is rare. Once allergic symptoms occur, patients should seek immediate medical attention. Treatment measures should be implemented according to the severity of symptoms, such as antiallergic therapy, oxygen administration, and medication including epinephrine and dexamethasone. In some cases, emergency interventions such as tracheotomy may also be required.