II. Definitions
III. Epidemiology
- No gender or age predominance
- Most common cause of diffuse Hair Loss
IV. Pathophysiology
- Altered growth cycle where Telogen phase predominates
- Timing
- Onset sudden, 2-4 months after inciting event
- Resolves months after causative factor resolves
V. Symptoms
VI. Signs
VII. Causes
- Idiopathic in some cases
- Endocrine disorders
- Nutritional Disorders
- Severe Iron Deficiency Anemia
- Crash dieting or significant dietary limitations (Malnutrition)
- Zinc Deficiency
- Stressors
- Severe chronic illness (liver disease or renal disease)
- Significant acute infection (high fever)
- Postpartum effluvium
- Major surgery
- Serious psychological stressors
- Medications
- Heparin and other Anticoagulants (e.g. Warfarin)
- Heavy Metals
- Etretinate (Tegison) and other Retinoids
- Anticonvulsants (e.g. Valproate)
- Antithyroid Drugs (e.g. Methimazole, PTU)
- Antidepressants (e.g. Fluoxetine)
- Isoniazid
- Hormonal agents
- Oral Contraceptive initiation or discontinuation
- Alkylating Agents
- Lithium
- Most common medication cause
- Antihypertensives
- Beta Blockers (e.g. Metoprolol, Propranolol)
- ACE Inhibitors
VIII. Differential diagnosis
- Early Androgenetic Alopecia
- Syphilis (consider if regrowth delayed)
IX. Associated Conditions
- Comorbid Androgenetic Alopecia is often present
X. Labs: Optional
- Thyroid Stimulating Hormone (TSH)
- Complete Blood Count
- Serum Iron and Serum Ferritin
- Comprehensive panel (chem18 with Serum Creatinine and Liver Function Tests)
- Consider Vitamin D Levels
XI. Management
- No treatment is needed in most cases (typically resolves spontaneously in 2-6 months)
- Treat underlying cause
- Eliminate suspected medication causes
- Consider labs as above
- Consider empiric 2 weeks of supplemental zinc if nuitritional deficiency suspected
- Consider Minoxidil during regrowth period if comorbid Androgenetic Alopecia is present
XII. Course
- Onset sudden, 2-4 months after inciting event (physiologic or emotional stressor)
- Typically self limited
- Resolves in 2 to 6 months (up to 9 months) spontaneously in most cases