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Scalp Pathology for the Hair Restoration Surgeon: Differentiating Chronic Telogen Effluvium from Female Pattern Hair Loss Bernard Nusbaum, M.D. Reprinted from Hair Transplant Forum International: I think that we can all agree that hair loss diagnosis in women presents a more formidable challenge than in their male counterparts. Since hair transplantation is contraindicated for certain alopecias, we need to approach the female candidate with a greater degree of awareness regarding the entire range of differential diagnostic possibilities. In previous editions, I addressed the distinguishing features of Diffuse Alopecia Areata1, 2 and Fibrosing Alopecia in a Pattern Distribution (FAPD)2, both imitators of Female Pattern Hair Loss (FPHL). This article will discuss how to differentiate patients with chronic, diffuse hair loss secondary to Chronic Telogen Effluvium (CTE) from those with early FPHL in whom a classic pattern is not easily identified. It should be noted that Acute Telogen Effluvium can occur in women with longstanding FPHL and, also, FPHL can initially manifest itself following an episode of Acute Telogen Effluvium. In those cases, the history of a precipitating factor such as childbirth, febrile illness, certain medications, crash dieting, etc., can be elucidated to have occurred approximately 3 months prior to the shedding episode and the shedding subsides in 3-6 months. Patients with CTE, however, experience shedding for longer than 6 months (some lasting several years) and are usually idiopathic although nutritional deficiencies, drugs, autoimmune or endocrine diseases can be possible causes.3 Appropriate blood work consisting of a CBC, Iron , Ferritin, ANA and Thyroid Profile should be performed in these patients. Clinical FeaturesAlthough FPHL can manifest itself after any hormonal change (i.e. the postmenopausal state), it typically has an early age of onset such as the late teens or early 20's, while CTE is predominantly seen in the 4th to 6th decade. The history of FPHL is typically that of gradual progressive thinning while CTE patients complain of excessive shedding which begins abruptly. The physical examination of classical FPHL reveals thinning which is most notable in the frontal and parietal areas with preserved density in the occipital scalp and a preserved rim of hair at the frontal hair line. A widened central part is seen in these patients due to increased spacing between hairs in the "top-scalp" area. CTE patients, on the other hand, generally present with normal hair density throughout, while some claim a decrease in ponytail volume. Although some women with FPHL exhibit bitemporal recessions, CTE patients have bitemporal thinning without associated thinning of the "top-scalp". Close inspection of FPHL reveals miniaturized hairs of varying short lengths and decreased caliber, while in CTE there is a general absence of miniaturized hairs. The hair pull test in FPHL may be normal or increased with telogen hairs in the top-scalp area with normal findings in the occiput. In CTE, increased numbers of telogen hairs are obtained throughout the scalp and to a greater degree than in FPHL. After reading the above description it might seem that differentiating the two entities presents little difficulty. In "real-life" however, things don't follow text-book descriptions and when FPHL is in its early stages, the classical pattern may not be apparent. Also, to complicate matters, women with early FPHL may present with episodic or continuous hair shedding. When a diagnosis is in doubt, we generally rely on scalp biopsy to make a diagnosis. HistopathologyExamination of horizontal sections allows study of larger numbers of follicular structures than vertical sections, thus making follicular counts more accurate4. The histologic differentiation between FPHL and CTE is based on determining the ratio of terminal to vellus hairs in horizontal sections.4,5 A ratio of <4:1 is indicative of FPHL while a ratio of >8:1 suggests the diagnosis of CTE. Intermediate ratios are considered to be "indeterminate" or "non-diagnostic". The general recommendation for scalp biopsies to diagnose alopecias is to perform two 4mm punch biopsies; one for horizontal and one for vertical sections. This protocol provides only one specimen for horizontal study. I would like to draw your attention to a study performed by Sinclair, et.al.5 (The reliability of horizontally sectioned scalp biopsies in the diagnosis of chronic diffuse telogen hair loss in women. J. Am. Acad. Dermatol. Volume 51, No. 2, Aug. 2004, pp. 189-199) which evaluated a single horizontal specimen versus three 4mm punch specimens sectioned horizontally in distinguishing FPHL from CTE. 305 women had a single horizontal biopsy and 207 women had triple biopsies from the mid scalp. In addition, the women who underwent triple biopsies were evaluated for hair-loss severity utilizing a 5 point mid-scalp clinical grading scale (5 being most severe). The investigators feel that this scale is more sensitive than the 3 point Ludwig scale. Women with stage 1 and 2 tended to present with either episodic or continuous increased hair shedding and most claimed a reduction in hair volume when held in a ponytail. Those with stages 3, 4 and 5 presented with loss of hair volume of over the top scalp with widening of the central part and had more severe thinning of the top scalp with increasing grade (the photo of their grade 5 looks like a Ludwig 2½ - 3). Stages 3, 4 and 5 patients also complained of episodic increased hair shedding or continuous hair shedding. Results showed that an accurate diagnosis was achieved in 98% of women who underwent triple biopsies as compared to 79% in those with a single horizontal biopsy. The number of cases in which a diagnosis was unable to be made on histologic grounds (indeterminate ratios) was reduced from 23% with single horizontal biopsy to 2% with triple biopsy. Among the women diagnosed histologically as having CTE, none were clinically assessed to have stage 4 or 5 hair loss and only 5% were assessed as stage 3. The authors advocate triple biopsy for women who present with early stages of FPHL in whom biopsy is considered to rule out CTE. The triple biopsy protocol is also recommended for patients with classic symptoms of CTE, such as diffuse, increased hair shedding, reduction in ponytail volume and bitemporal recession with absence of widening of the central part. Patient compliance for triple biopsy was high since the 3 biopsies were taken from one site, adjacent to each other, and sutured in a continuous fashion. The classical protocol of two specimens involves two, separate anesthesia infiltrations and two separate biopsy sites. It should be noted that the classical biopsy protocol should not be abandoned in the setting of a more advanced Ludwig pattern since a vertical and horizontal specimen may be useful to rule out FAPD. Generally, we justify performing a diagnostic procedure based on the fact that it will alter treatment and management. While topically applied minoxidil and work up to identify possible underlying factors is probably all we can do for CTE patients, it is important to establish the diagnosis firmly so we can also reassure them that their condition is resulting in hair shedding and not progressive hair loss (as in FPHL) and that they will get better with time. References
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