In a 27-year-old woman 8 weeks postpartum presenting with diffuse, non-scarring hair loss and new hair growth, what is the most appropriate next step to establish the diagnosis?

Postpartum Telogen Effluvium: Hair Pull Test for Diagnosis

Perform the hair pull test to confirm the diagnosis of postpartum telogen effluvium in this patient. 1

Clinical Reasoning

This 27-year-old woman presents with a classic picture of postpartum telogen effluvium:

• Timing: Hair loss began 8 weeks postpartum, which falls within the typical 2-4 month window when physiologic stressors (childbirth) push hair follicles prematurely into the telogen (resting) phase 1
• Pattern: Diffuse hair loss with clumped shedding during washing and brushing, rather than discrete patches 1
• Evidence of recovery: New hair growth is already visible, indicating the self-limited nature of this condition 1
• Absence of inflammatory signs: No erythema or induration rules out tinea capitis and scarring alopecias 1
• Negative systemic symptoms: No anxiety, diarrhea, or heat intolerance excludes hyperthyroidism 1

Why the Hair Pull Test is the Correct Next Step

The hair pull test is a simple, non-invasive bedside diagnostic tool that involves gently tugging on a cluster of approximately 40-60 hairs to assess their fragility. 2, 1

• In telogen effluvium, the test is positive when >6 hairs are easily extracted, confirming excessive telogen shedding 1, 3
• The test helps differentiate telogen effluvium from other causes of diffuse hair loss 4, 3
• No laboratory testing is required when the clinical presentation is this straightforward 1, 5

Why Other Options Are Incorrect

Nikolsky Sign

• This test assesses for blistering skin diseases (pemphigus, toxic epidermal necrolysis) by applying lateral pressure to induce epidermal separation 1
• Completely irrelevant to non-scarring alopecia 1

Skin Scrapings for Budding Hyphae

• Fungal culture is indicated only when scalp inflammation or scaling suggests tinea capitis 1, 5
• This patient has no inflammation, no scaling, and no erythema—making fungal infection extremely unlikely 1

Serum Folate Level

• Folate deficiency may contribute to hair loss, but routine nutritional testing is unnecessary when the diagnosis of postpartum telogen effluvium is clinically evident 1, 5
• Laboratory testing should be reserved for atypical presentations or diagnostic uncertainty 1, 5

Serum Magnesium Level

• Magnesium deficiency is not a recognized cause of postpartum hair loss 1
• This test has no role in the evaluation of telogen effluvium 1, 5

Expected Clinical Course and Management

Reassurance is the cornerstone of management, as 34-50% of patients with short-duration telogen effluvium experience spontaneous resolution within one year. 1, 5

• Counsel the patient that visible regrowth is unlikely within the first 3 months, but the presence of new hair growth already indicates recovery is underway 5
• Removal of the precipitating trigger (in this case, the physiologic stress of childbirth has already resolved) leads to spontaneous remission in up to 80% of cases with duration <1 year 5
• No pharmacologic intervention is required for postpartum telogen effluvium 1, 5

Common Pitfalls to Avoid

• Do not order extensive laboratory panels (thyroid function, iron studies, vitamin levels) when the clinical picture clearly indicates postpartum telogen effluvium 1, 5
• Do not confuse this with alopecia areata, which presents with discrete patches, exclamation-mark hairs on dermoscopy, and yellow dots—none of which are present here 1, 5
• Do not overlook the psychological impact of hair loss; address emotional distress and provide reassurance about the excellent prognosis 1, 5