What is the medical term for seasonal hair loss in adults?

Seasonal Hair Loss: Medical Terminology

The medical term for seasonal hair loss is "seasonal telogen effluvium," a variant of telogen effluvium where physiological stressors push hair follicles prematurely into the resting (telogen) phase, resulting in increased shedding that follows seasonal patterns. 1, 2

Understanding Telogen Effluvium

Telogen effluvium represents one of the most common causes of diffuse hair loss, characterized by excessive shedding of club (telogen) hairs across the entire scalp. 2, 3

Key Characteristics

• The condition occurs when hair follicles are precipitated prematurely from the active growth phase (anagen) into the resting phase (telogen), leading to synchronous shedding weeks to months later. 3

• Shedding typically becomes noticeable 2-3 months after the triggering event, as this represents the time required for hairs to complete the telogen phase and shed. 2

• The degree of shedding can be severe in early stages, with hair sometimes coming out in handfuls, though this represents shedding rather than permanent hair loss. 4

Clinical Presentation Patterns

Acute vs. Chronic Forms

• Acute telogen effluvium is self-limiting and resolves once the triggering factor is removed, typically within 6 months. 2, 5

• Chronic telogen effluvium persists beyond 6 months and tends to fluctuate over years, most commonly affecting women aged 30-60 years who previously had full hair. 4

• Chronic telogen effluvium has an abrupt onset with or without recognizable initiating factors, and patients fear total baldness despite reassurance that complete baldness does not occur. 4

Common Triggers

• Physiological stressors include illness, surgery, childbirth, rapid weight loss, and nutritional deficiencies. 1, 2

• Emotional stress and trauma can precipitate episodes. 2, 6

• Medications (particularly chemotherapy, anticoagulants, and beta-blockers) may trigger telogen effluvium. 1

Diagnostic Approach

Clinical Evaluation

• Look for diffuse thinning without the characteristic patterns seen in androgenetic alopecia (which shows crown thinning with frontal hairline preservation). 1

• Perform a hair pull test at the margins, which will be positive during active shedding phases. 1

• Dermoscopy distinguishes telogen effluvium from other causes: absence of yellow dots and exclamation mark hairs differentiates it from alopecia areata. 1

Diagnostic Tests Available

• Hair wash test quantifies daily shedding (normal is <100 hairs per day). 2

• Trichogram and phototrichogram assess the percentage of hairs in telogen phase (>20% suggests telogen effluvium versus normal 10-15%). 2

• Scalp biopsy provides definitive diagnosis when clinical presentation is unclear. 2

Laboratory Workup

When diagnosis is uncertain or presentation is atypical, targeted laboratory testing helps identify underlying triggers: 1

• Serum ferritin levels (iron deficiency causes chronic diffuse telogen hair loss). 1

• Vitamin D levels (deficiency <20 ng/mL shows strong association with hair loss). 1

• Thyroid stimulating hormone (TSH) to exclude thyroid disease. 1

• Serum zinc levels (deficiency impairs hair follicle function). 1

Management Strategy

Primary Approach

• The essential first step is identifying and removing causative factors, as telogen effluvium is usually self-limiting once triggers are addressed. 2, 6

• Provide repeated reassurance that the condition represents shedding rather than permanent hair loss and does not cause complete baldness. 4, 6

Treatment Options

• Corticosteroids may be used in select cases. 2

• Minoxidil can promote hair regrowth during recovery. 2

• Novel treatments include CNPDA (caffeine, niacinamide, panthenol, dimethicone, and an acrylate polymer). 2

Nutritional Supplementation

• Vitamin D supplementation for levels <20 ng/mL. 1

• Zinc supplementation when deficient. 1

• Iron supplementation when ferritin is low. 1

Common Pitfalls to Avoid

• Failing to distinguish telogen effluvium from early androgenetic alopecia, which may coexist and requires histology for definitive diagnosis. 3

• Ordering excessive laboratory tests when clinical diagnosis is evident through history and dermoscopy. 1

• Underestimating the psychological impact—patients experience significant distress and require education about the self-limiting nature and excellent prognosis. 6, 5

• Missing chronic telogen effluvium, which fluctuates over years and requires long-term management and reassurance. 4