A 65-year-old woman who is otherwise healthy with normal laboratory studies presents with sudden diffuse hair shedding after a recent hospitalization for COVID-19 and influenza; what is the likely diagnosis and how should she be managed?

Telogen Effluvium Secondary to COVID-19 Infection

This is acute telogen effluvium (TE) triggered by her recent COVID-19 and influenza hospitalization, and you should reassure her that spontaneous recovery is expected within 3-6 months, though topical minoxidil 5% can accelerate improvement.

Diagnosis

This presentation is classic for post-COVID-19 acute telogen effluvium 1, 2. The key diagnostic features align perfectly:

• Timing: Hair shedding typically begins 2-3 months (mean 74 days) after COVID-19 symptom onset 1, 2, which is earlier than classic acute TE
• Pattern: Diffuse hair shedding without scarring
• Demographics: Women have approximately 5-fold higher risk compared to men 3
• Severity correlation: Hospitalization for COVID-19 significantly increases TE risk, with severity of systemic inflammation (elevated CRP >1.90 mg/L, IL-1β >5 ng/L) being key drivers 3

The normal laboratory studies appropriately exclude other causes (thyroid dysfunction, iron deficiency, nutritional deficiencies), making this a diagnosis of exclusion consistent with long COVID manifestations 4.

Pathophysiology

The mechanism involves the severe physiological stress from COVID-19 infection pushing hair follicles prematurely from anagen (growth phase) into telogen (resting phase), resulting in synchronized shedding 2-3 months later 5, 1. The severity of inflammation appears more important than hormonal factors in triggering this process 3.

Management Approach

Immediate Steps

1. Confirm diagnosis with hair pull test: Should be strongly positive (>10-50% of pulled hairs coming away from scalp) 2

2. Provide definitive reassurance: Most patients achieve spontaneous recovery as this is self-limiting 1, 6. Hair loss typically lasts up to 6 months from onset

3. Initiate topical minoxidil 5%: While spontaneous recovery occurs, topical minoxidil can accelerate symptom improvement and reduce the psychological burden 5. This is the only treatment with supporting evidence for post-COVID TE

Monitoring

• Follow-up in 3 months to assess recovery trajectory
• If hair loss persists beyond 6 months or worsens, reconsider alternative diagnoses (androgenetic alopecia exacerbation, alopecia areata) 5, 6

Critical Caveats

Do not confuse this with other alopecia types: While COVID-19 is associated with androgenetic alopecia (AGA) and alopecia areata (AA), these present differently 6:

• AGA typically preceded COVID-19 (not new onset)
• AA usually represents relapse in patients with preexisting disease (95.1% of cases) 6
• TE is the predominant new-onset hair loss pattern post-COVID (93.6% newly triggered) 6

Psychological impact matters: Despite being self-limiting, hair loss causes substantial mental burden and affects quality of life 5, 1. Addressing this directly through education and treatment accelerates psychological recovery even if physical recovery timelines are similar.

The evidence consistently shows this is a recognized long COVID manifestation 7, 4 that requires acknowledgment and supportive management rather than extensive additional workup given her normal laboratories.