Ibuprofen and Fever: Side Effect, Causes, and What Patients Can Do

Ibuprofen can, in rare cases, be associated with fever as part of a hypersensitivity or severe skin reaction, even though it is commonly used to reduce fever. ^[1] Ibuprofen product information advises stopping the drug immediately if a rash or fever develops and contacting a healthcare provider. ^[2]

How Ibuprofen Might Be Linked to Fever

• Hypersensitivity reactions: Fever can appear with allergic-type reactions to ibuprofen, sometimes alongside rash, blisters, itching, or other systemic symptoms. ^[3] Similar guidance notes fever may be one of the warning signs of serious skin reactions (including DRESS). ^[4]

• Systemic reactions reported: Clinical listings of adverse reactions for ibuprofen include fever among possible systemic effects in some patients. ^[5] These reactions can mimic infection and warrant medical evaluation. ^[5]

• Important nuance: Ibuprofen’s usual pharmacologic action lowers fever, which can mask signs of complications, but a paradoxical fever may signal an adverse reaction rather than the intended antipyretic effect. ^[6] This masking effect is described across ibuprofen labeling. ^{[7] [8]}

What Symptoms Should Prompt Action

• Stop ibuprofen and seek care if you develop fever with any rash, blisters, facial swelling, hives, wheezing, or other signs of allergy. ^{[1] [9]}
• Seek urgent care if fever is accompanied by severe headache, stiff neck, confusion, chest pain, difficulty breathing, low blood pressure, or persistent vomiting. ^[5]

Key safety advice: Patients are specifically advised to stop the drug immediately if a rash or fever occurs and contact their healthcare provider as soon as possible. ^{[2] [1]}

Practical Steps to Cope Safely

• Discontinue ibuprofen at once if fever occurs after starting it, especially with any rash or hypersensitivity signs. ^{[2] [1]}
• Switch to acetaminophen (paracetamol) for comfort if you need a fever reducer and have no contraindications, while you arrange medical advice. Guidance on fever treatment for adults supports using an antipyretic for fevers above 38.9°C (102°F) to reduce discomfort. ^[10] Using acetaminophen in pregnancy to manage fever is also commonly recommended when appropriate. ^[11]
• Hydrate and rest while monitoring temperature and symptoms, and avoid further NSAID doses until evaluated. ^[10]
• Call your clinician if fever does not improve or lasts longer than about three days, or sooner if you feel worse. ^{[12] [13]}

Important caution: Because ibuprofen typically reduces fever, a new or worsening fever while taking it may be a red flag rather than a routine symptom. ^{[6] [7]}

When to Seek Emergency Care

• Immediate medical evaluation is warranted for fever with signs of severe allergic reaction (rash with blisters, facial swelling, breathing trouble), or systemic instability (marked hypotension, severe chills/rigors). ^{[3] [5]}
• Stop ibuprofen and get urgent help if you experience fever plus widespread rash or mucous membrane involvement, which can indicate serious skin reactions. ^{[3] [4]}

Who Is at Higher Risk

• History of aspirin allergy/asthma: Ibuprofen can trigger severe allergic reactions in those with aspirin sensitivity. ^[9]
• Underlying conditions: Labeling warns that ibuprofen’s fever-lowering action can obscure clinical signs in painful conditions, so clinicians may be cautious where complications are being monitored. ^{[6] [7]}

Bottom Line

• Yes, fever can occur as a rare adverse reaction to ibuprofen, often as part of hypersensitivity or serious skin reactions. ^{[1] [2]}
• If fever develops while taking ibuprofen especially with any rash or allergy signs stop the drug and contact a healthcare provider promptly. ^{[2] [1]}

Staying alert to warning signs and acting early helps keep you safe while managing pain or fever. ^[1]