Table 2.

Workup for female pattern hair loss

Test	Findings	Indications
Patient interview/history	Hair loss from roots	Alopecia areata, telogen effluvium, anagen effluvium, androgenetic alopecia
	Hair breakage	Tinea capitis, trichotillomania, damage from cosmetics/heat (trichoschisis, bubble hair), structural abnormalities (Menke’s kinky hair, uncombable hair syndrome, monilethrix)
	Medical and psychiatric history, including recent illnesses, pregnancy, hospitalizations, and symptoms such as weight loss or fatigue	Telogen effluvium, hypothyroidism, trichotillomania, medication- induced alopecia
	Dietary intake	Nutritional deficiency
	Family history	Androgenetic alopecia, hypothyroidism, alopecia areata
	Medications/chemotherapeutics, illicit substances	Medication-induced hair loss, anagen effluvium
	Menstrual/menopause history, use of OCP or hormones	Endocrinopathy, androgenetic alopecia, medication-induced hair loss
	Hair care practices and styling	Traction alopecia, CCCA, pseudopelade
Physical exam	Scarring versus nonscarring	Multiple etiologies (see Table 1)
	Patchy hair loss	Syphilis, SLE/DLE, nutritional deficiency, monilethrix, alopecia areata
	Thinning on vertex and midline scalp with sparing of frontal hair line	Androgenetic alopecia
	Vertex thinning with loss of follicular ostia	CCCA, pseudopelade
	Erythema, scale, hair breakage, kerion, occipital lymphadenopathy	Tinea capitis
	Signs of virilization, hirsutism, acne	Androgenetic alopecia, endocrinopathy, systemic disease
	Perifollicular erythema Pustules	LPP, alopecia areata (early)Pustular folliculitis (decalvans,dissecting cellulitis, acne)
Pull test	0–5 hairs removed	Normal, androgenetic alopecia, trichotillomania
	≥6 hairs removed	Alopecia areata, telogen effluvium, loose anagen syndrome, medication-induced alopecia
Hair mount	Hair with no inner root sheath and bulb with club shape	Telogen hair
	Large and pigmented bulb with inner root sheath	Anagen hair
	Nodes along the hair shaft accompanied by breakage (paint brush fracture)	Trichorrhexis nodosa, (Menke’s kinky hair syndrome, Argininosuccinic aciduria)
	Intussusception of distal into proximal hair shaft (bamboo hair)	Trichorrhexis invaginata (Netherton’s syndrome)
	Tiger-tail banding	Trichothiodystrophy, medication- induced alopecia
KOH mount	Fungal spores present either on or in the hair shaft	Tinea capitis
	Nodules or gelatinous sheaths along hair shafts	Piedra, hair casts, pityriasis amiantacea, head lice
Laboratory tests	CBC and iron panel	Anemia
	Thyroid panel	Hypothyroidism
	Vitamin D, Vitamin A, Vitamin C, zinc, biotin, folic acid	Nutritional deficiency
	ANA screen	SLE/DLE
	RPR/VDRL	Syphilis
	Prolactin, free and bound testosterone, DHEAS, LH, FSH	Endocrinopathy, systemic disease
Scalp biopsy	Increased number of vellus hairs, uninvolved area, normal follicle count	Androgenetic alopecia
	Absence of inflammation with increased telogen count	Telogen effluvium
	Peribulbar lymphocytic infiltrate, increased telogen and catagen hairs	Alopecia areata
	Band-like lymphocytic infiltrate at interface between dermis and follicular epidermis; perifollicular fibrosis	LPP
	Vacuolar interface with superficial and deep perivascular and periadnexal lymphocytic inflammation; follicular plugging	DLE
	Perifollicular mixed inflammatory infiltrate (primarily neutrophilic) with destruction of hair follicles and sebaceous glands, naked hair shafts in dermis; surrounding granulomatous infiltrate (multinucleated giant cells) and fibrosis	Pustular folliculitis (acne keloidalis, folliculitis decalvans, dissecting cellulitis)
	Decreased number or absent terminal hairs, dermal fibrosis; plasma cells	Scarring alopecia

Abbreviations: ANA, antinuclear antibody; CBC, complete blood count; CCCA, central centrifugal cicatricial alopecia; DHEAS, dehydroepiandrosterone sulfate; DLE, discoid lupus erythematosus; FSH, follicle-stimulating hormone; LH, luteinizing hormone; LPP, lichen planopilaris; OCP, oral contraceptives; RPR, rapid plasma regain; SLE, systemic lupus erythematosus; VDRL, venereal disease research laboratory.