Inflammatory flare-ups

An inflammatory flare-up (often shortened to “flare”) is a temporary but noticeable worsening of symptoms and objective disease activity in a chronic inflammatory condition after a period of relative stability or remission. In clinical language, a flare corresponds to an exacerbation: signs and symptoms intensify because inflammatory pathways are more active than baseline. People experience flares differently depending on the organ system involved—for example, swollen and painful joints in inflammatory arthritis, a red and itchy rash in eczema, shortness of breath and wheeze in asthma, or abdominal pain and diarrhea in inflammatory bowel disease (IBD). Although the word “exacerbation” is common in medical literature, many professional groups encourage “flare-up” for patient-friendly communication.

Where the term is used

Inflammatory flare-ups are discussed across multiple specialties:

• Rheumatology: rheumatoid arthritis and other inflammatory arthritides commonly wax and wane; patient-reported flares and clinician-assessed flares are central to treatment decisions and research.

• Dermatology: atopic dermatitis (eczema) and psoriasis often relapse in “flares,” prompting step-up topical or systemic therapy.

• Pulmonology/allergy: asthma guidelines describe “flare-ups” (severe exacerbations) and emphasize written action plans to recognize and treat them promptly.

• Gastroenterology: in IBD (Crohn’s disease and ulcerative colitis), flares mark a return or escalation of gastrointestinal and systemic symptoms after remission.

Features and clinical recognition

Typical features include a sudden or subacute increase in symptom intensity, functional limitation, and sometimes measurable inflammatory markers. What counts as a flare varies by disease and context:

• Patient perspective: early “red flags” such as unusual fatigue, sleep disturbance, or localized pain often precede maximal symptoms, and many care models encourage patients to track these early warnings in symptom diaries.

• Clinician perspective: some fields use formal indices to define flares (for example, validated changes in rheumatoid arthritis composite scores). In respiratory disease, severity labels (mild, moderate, severe) and objective measures (oxygen saturation, peak flow) help standardize assessment.

• Biomarkers and tests: clinicians may use blood inflammatory markers (e.g., C‑reactive protein, erythrocyte sedimentation rate) or condition-specific tests such as fecal calprotectin in IBD, recognizing that these markers support—but do not replace—clinical judgment.

Common triggers

Flares can be predictable (linked to a known trigger) or unpredictable. Frequent triggers include intercurrent infections, medication lapses or dose reductions, psychological stress, sleep deprivation, overexertion, exposure to irritants or allergens (e.g., tobacco smoke, fragrances, dust mites), weather and humidity extremes, and hormonal shifts. Sometimes no clear trigger is identified, reflecting natural fluctuations in immune activity.

Why inflammatory flare-ups matter

• Quality of life and function: flares can be painful, disabling, and emotionally taxing, impacting work, school, and caregiving.

• Organ protection and long-term outcomes: repeated or prolonged flares are associated with structural damage in some conditions (e.g., joint damage in inflammatory arthritis, airway remodeling in asthma, mucosal injury in IBD).

• Safety: severe flares in the lungs or gut can become medical emergencies; distinguishing a sterile flare from infection is critical, particularly for people on immunosuppressive medications.

Management principles

Treatment is individualized to the underlying condition and the flare’s severity, but broad principles include:

• Follow a written action plan when available (common in asthma and increasingly used in other chronic diseases). Plans outline how to adjust reliever and controller therapies, when to start short courses of anti-inflammatory medicines if prescribed, and when to seek urgent care.

• Identify and address triggers: treat infections promptly, minimize exposure to irritants or allergens, and review recent medication changes.

• Symptom relief and self-care: targeted rest while maintaining gentle range-of-motion in affected joints, heat or cold for musculoskeletal pain, meticulous skin care and moisturization in eczema, hydration and dietary adjustments during IBD flares as advised by clinicians.

• Early contact with the care team: many guidelines recommend expedited follow-up after severe flare-ups to reassess control, update the action plan, and consider step-up therapy or preventive strategies (for example, vaccinations and smoking cessation).

• Monitoring: depending on the disease, clinicians may follow symptoms, physical findings, and biomarkers (e.g., CRP/ESR, fecal calprotectin) to gauge resolution and guide therapy.

Prevention and self-management

While not all flares are preventable, risk can be reduced by:

• Adhering to maintenance therapies as prescribed and not tapering medications without medical guidance.

• Using trigger-reduction strategies: consistent moisturization and gentle products for eczema; allergen and smoke avoidance for asthma; individualized nutrition guidance for IBD; pacing of physical activity and stress-management techniques for arthritis and other autoimmune diseases.

• Keeping a personalized symptom and trigger diary and sharing it with the care team to refine prevention and early-intervention steps.

When to seek urgent care

Immediate medical attention is warranted for red-flag signs such as severe breathing difficulty, chest pain, confusion, high fever with chills in an immunosuppressed person, signs of severe dehydration, heavy rectal bleeding, uncontrolled vomiting, or neurologic symptoms. When in doubt, err on the side of prompt evaluation.

Sources

• Global Initiative for Asthma (GINA). Guidance on terminology (“flare-up” for patient-facing communication), written action plans, and follow-up after severe exacerbations. https://pmc.ncbi.nlm.nih.gov/articles/PMC9907191/ and https://pmc.ncbi.nlm.nih.gov/articles/PMC4554554/

• Centers for Disease Control and Prevention (CDC). IBD basics; definition of flares vs. remission and symptom patterns. https://www.cdc.gov/inflammatory-bowel-disease/about/index.html

• Crohn’s & Colitis Foundation. Patient-friendly definitions and recognition of IBD flares. https://www.crohnscolitisfoundation.org/flare and https://www.crohnscolitisfoundation.org/patientsandcaregivers/ibd-me/what-is-a-flare-comic

• NCBI MedGen. General medical concept of “symptom flare-up” as a transient exacerbation of an existing condition. https://www.ncbi.nlm.nih.gov/medgen/875730

• Arthritis Foundation. Explanations and practical strategies around arthritis flares. https://www.arthritis.org/health-wellness/healthy-living/managing-pain/pain-relief-solutions/what-is-a-flare and https://www.arthritis.org/health-wellness/healthy-living/managing-pain/pain-relief-solutions/tips-for-managing-an-arthritis-flare

• University of Nottingham, Centre of Evidence-Based Dermatology. Definitions and measurement issues for “flare” in atopic dermatitis. https://www.nottingham.ac.uk/research/groups/cebd/resources/flare-atopic-dermatitis.aspx

• NCBI Bookshelf (StatPearls). Eczema management principles, including flare care and trigger avoidance. https://www.ncbi.nlm.nih.gov/books/NBK538209/

• PubMed/ACR Open Rheumatology and related literature. Evolving definitions and predictors of rheumatoid arthritis flares, and the role and limitations of biomarkers (CRP/ESR) across diseases. https://pubmed.ncbi.nlm.nih.gov/37890977/ and https://pubmed.ncbi.nlm.nih.gov/30123796/

• Johns Hopkins Medicine. Background on IBD as a chronic inflammatory condition with relapsing flares. https://www.hopkinsmedicine.org/health/conditions-and-diseases/inflammatory-bowel-disease

• MedlinePlus (NIH). Ulcerative colitis overview noting that stress and certain foods can trigger symptoms during flares. https://medlineplus.gov/ency/article/000250.htm

• American Journal of Gastroenterology and PubMed. Clinical use of fecal calprotectin as a noninvasive marker to monitor IBD flare activity. https://journals.lww.com/ajg/fulltext/2025/11000/fecal_calprotectin_correlates_with_disease_extent.30.aspx and https://pubmed.ncbi.nlm.nih.gov/26125109/

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