Can alopecia recurrence be triggered by common illnesses like the flu or COVID-19?

Alopecia—an umbrella term for hair loss—can recur or worsen after common illnesses such as the flu or COVID-19. Understanding how “illness triggered alopecia” works, what types of hair loss are most often involved, and when to seek medical advice can help you navigate this often distressing symptom without undue anxiety.

What Is “Illness Triggered Alopecia”?
“Illness triggered alopecia” refers to hair shedding or bald patches that appear after a physical stressor—often an infection or fever. Two main patterns are:

• Alopecia Areata (AA): An autoimmune condition where the body’s immune system attacks hair follicles, leading to round or oval bald spots.
• Telogen Effluvium (TE): A reactive process in which a large number of hairs prematurely enter the resting (telogen) phase, causing diffuse shedding across the scalp.

Both AA and TE can be set off—or see a recurrence—after illnesses that push the body’s immune and stress systems into overdrive.

How Common Illnesses Can Trigger Hair Loss

1. Immune System Activation

   • Viral and bacterial infections ramp up inflammatory cytokines (immune-signaling molecules).
   • In genetically predisposed individuals, heightened immune activity can mistakenly target hair follicles (as in AA).

2. Physical and Emotional Stress

   • Fever, severe fatigue, hospitalization and psychological stress all impact the hair cycle.
   • After a major stressor, up to 70% of hairs can shift into the telogen phase.

3. Nutritional and Metabolic Effects

   • Illness often reduces appetite and alters nutrient absorption.
   • Deficiencies in iron, zinc, biotin or protein can worsen shedding, especially in TE.

Evidence from Recent Studies
Rossi & Magri (2020) “De novo onset and recurrence of alopecia areata…”

• In a small case series, both new-onset and recurrent AA were observed shortly after COVID-19 infection.
• Patients developed sudden bald patches 2–8 weeks post-infection, suggesting a COVID-linked immune trigger.

Moreno-Arrones & Saceda-Corralo (2021) “Telogen effluvium after COVID-19…”

• Among 214 patients recovering from COVID-19, 20% reported significant diffuse hair shedding (TE) 2–3 months later.
• Severity of TE correlated with the intensity of the initial illness (e.g., days of fever or oxygen therapy).

European Association for the Study of the Liver (EASL) Clinical Practice Guidelines (2018)

• Although focused on liver disease, the guidelines highlight that any acute infection—including viral hepatitis—can lead to TE.
• Recovery from the underlying illness generally allows hair to return over 6–12 months, provided nutritional needs are met.

Key Takeaways on Illness-Triggered Alopecia
• Timing:

• TE usually appears 1 to 3 months after the illness.
• AA recurrence or new onset may occur within weeks.

• Pattern of Hair Loss:

• TE: Diffuse thinning, especially noticeable when washing or brushing hair.
• AA: Discrete, round patches of baldness.

• Prognosis:

• TE is often self-limited; hair regrows once stress resolves and nutrient levels normalize.
• AA may require medical treatment to halt progression and stimulate regrowth.

Preventing and Managing Post-Illness Hair Loss
Although you can’t always prevent “illness triggered alopecia,” you can take steps to minimize its impact:

1. Optimize Nutrition

   • Ensure adequate protein, iron, zinc and vitamins (especially D and B complex).
   • Consider lab tests to rule out deficiencies.

2. Control Inflammation

   • Follow your doctor’s guidance on managing fevers and infections promptly.
   • Discuss anti-inflammatory diets or supplements if appropriate.

3. Reduce Stress

   • Practice relaxation techniques: deep breathing, yoga or meditation.
   • Prioritize sleep—aim for 7–9 hours per night.

4. Monitor Early Signs

   • Notice increased shedding in the shower or on your brush.
   • Look for round patches or thinning areas.

When to Seek Professional Help
• Severe or persistent hair loss beyond 6 months
• Rapidly expanding bald patches (suggesting active AA)
• Signs of systemic illness: high fevers, weight loss, fatigue

You might consider doing a free, online symptom check for Alopecia Areata to get a better sense of your risk and next steps.

Speak to a doctor if you experience any life-threatening symptoms (e.g., difficulty breathing, chest pain, severe weakness) or if hair loss significantly impacts your quality of life. Early evaluation by a dermatologist or primary care provider can help distinguish between TE and AA and guide appropriate treatment.

In Summary

• Common illnesses like the flu or COVID-19 can trigger both telogen effluvium and a recurrence of alopecia areata through immune activation and stress pathways.
• TE typically presents as diffuse hair shedding a few months post-illness and often resolves on its own.
• AA may flare up shortly after infection and can benefit from medical therapies (e.g., topical or injectable steroids).
• Good nutrition, stress management and timely medical care are your best defenses against illness-triggered alopecia.
• For personalized guidance, try a free “symptom check for Alopecia Areata” and speak to your doctor about any concerning or serious symptoms. Continuous follow-up ensures you get the most effective, tailored treatment plan.