Histopathology of Scarring and Nonscarring Hair Loss

The role of hair follicle counts and ratios in the histopathological assessment of androgenic alopecia, alopecia areata and telogen effluvium: does counting 'count'?

The histopathological assessment of scalp biopsies for the diagnosis of alopecia is most commonly undertaken in specialist centers. Occasionally, pathologists encounter such specimens outside a specialist setting or at a low frequency, which makes a confident diagnosis difficult. A methodical approach is essential to identify and interpret the histopathological findings, and one of the diagnostic tools is the use of follicular counts and ratios. This method is particularly emphasized in the context of non-scarring alopecia and, furthermore, for the identification of alopecias with overlapping features. We raised the question as to what is the role of follicular hair counts and ratios in the differential diagnosis of non-scarring alopecia with overlapping features, and sought the answer in our literature review. The English literature on the histopathological assessment of horizontal scalp biopsies taken for the evaluation of non-scarring alopecia, focusing on hair follicle counting as a diagnostic tool, with particular emphasis on androgenetic alopecia, alopecia areata, and telogen effluvium, was reviewed. Follicular counts and ratios are a helpful diagnostic tool. However, these need to be coupled with the morphological features specific for each alopecia subtype to render a confident diagnosis.

Alopecia Areata: an Update on Etiopathogenesis, Diagnosis, and Management

Alopecia areata (AA) is a common chronic tissue-specific autoimmune disease, resulting in hair loss, that affects up to 2% of the general population. The exact pathobiology of AA has still remained elusive, while the common theory is the collapse of the immune privilege of the hair follicle caused by immunological mechanism. Multiple genetic and environment factors contribute to the pathogenesis of AA. There are several clinical treatments for AA, varying from one or multiple well-defined patches to more diffuse or total hair loss of the scalp (alopecia totalis) or hair loss of the entire body (alopecia universalis). The available treatments for AA, such as corticosteroids and other immunomodulators, minoxidil, and contact immunotherapy, are of limited efficacy with a high risk of adverse effects and high recurrence rates, especially for patients with severe AA. Recent insights into the pathogenesis of AA have led to the development of new treatment strategies, such as Janus kinase (JAK) inhibitors, biologics, and several small molecular agents. In addition, modern therapies for AA, including antihistamines, platelet-rich plasma (PRP) injection, and other novel therapies have been well explored. In this review, we discussed the recent advances in the pathogenesis, diagnosis, and treatment of AA.

Ultra high-frequency ultrasound with seventy-MHz transducer in hair disorders: Development of a novel noninvasive diagnostic methodology

BACKGROUND

Ultra high-frequency ultrasound (uHFUS) is a recently developed diagnostic technology. Despite its potential usefulness, no study has assessed its advantage in diagnosis and evaluation of hair disorders in comparison with other diagnostic methods.

OBJECTIVES

To assess the practicability of uHFUS in diagnosing hair disorders and propose a diagnostic methodology.

METHODS

Ultrasonographic images of scalp and forehead from patients with hair disorders (n = 103) and healthy controls (n = 40) were obtained by uHFUS and analyzed by both descriptive and numerical parameters. Furthermore, the data were compared with trichoscopic and histopathological findings.

RESULTS

The pattern of inflammation and fibrosis, hair cycle abnormality, and the findings in subcutis were detected by uHFUS. Significant differences were noted in the numerical parameters associated with the number of hair shafts and follicles, hair diameters and their diversity, and dermal echogenicity in both cicatricial and non-cicatricial hair disorders. Findings in uHFUS were associated with those observed in trichoscopy and scalp biopsy but uHFUS was able to detect pathological findings associated with hair cycle, inflammation, fibrosis, and subcutaneous abnormalities, which are hardly assessable by trichoscopy.

CONCLUSION

The findings of this study highlighted usefulness of uHFUS in diagnosing hair disorders, while overcoming the weaknesses and limitations of other diagnostic tools.

Medical therapy for frontal fibrosing alopecia: A review and clinical approach

BACKGROUND

Guidelines for the treatment of frontal fibrosing alopecia (FFA) are limited, and the literature on treatment modalities consists mostly of case reports and cohort studies.

OBJECTIVES

In this review, we sought to assess the response of medical therapy for FFA and propose a clinical approach to management.

METHODS

A literature search for "frontal fibrosing alopecia" on PubMed returned 270 items. In this review, only studies with treatment regimens and reported outcomes were considered. The majority of studies found were case reports and retrospective cohort studies. Response to therapy was assessed by reported ability to slow or arrest hair loss.

RESULTS

Intralesional steroids and 5α-reductase inhibitors were the most commonly used therapies with the most positive treatment responses (88%, 181/204 for intralesional steroids and 88%, 158/180 for 5α-reductase inhibitors). Oral prednisone was seldom used and only temporarily delayed rapid hair loss. Other therapies evaluated included topical steroids, antibiotics, pioglitazone, systemic retinoids, and hair transplantation.

LIMITATIONS

Lack of placebo control studies and uniform outcome measures.

CONCLUSION

The natural course of FFA is variable. Recession of the frontal hairline might stabilize regardless of treatment. However, early intervention is encouraged in active disease because hair loss is presumed permanent and treatment could modify the disease course.

Primary cicatricial alopecia: Lymphocytic primary cicatricial alopecias, including chronic cutaneous lupus erythematosus, lichen planopilaris, frontal fibrosing alopecia, and Graham-Little syndrome

Both primary and secondary forms of cicatricial alopecia have been described. The hair follicles are the specific target of inflammation in primary cicatricial alopecias. Hair follicles are destroyed randomly with surrounding structures in secondary cicatricial alopecia. This 2-part continuing medical education article will review primary cicatricial alopecias according to the working classification suggested by the North American Hair Research Society. In this classification, the different entities are classified into 3 different groups according to their prominent inflammatory infiltrate (ie, lymphocytic, neutrophilic, and mixed). Part I discusses the following lymphocytic primary cicatricial alopecias: chronic cutaneous lupus erythematosus, lichen planopilaris, frontal fibrosing alopecia, and Graham-Little syndrome.

Primary cicatricial alopecia: Other lymphocytic primary cicatricial alopecias and neutrophilic and mixed primary cicatricial alopecias

Primary cicatricial alopecias can be frustrating for both patients and physicians. Proper diagnosis guides more successful management of these challenging conditions. Part II will cover the remaining lymphocytic primary cicatricial alopecias, which include pseudopelade of Brocq, central centrifugal cicatricial alopecia, alopecia mucinosa, and keratosis follicularis spinulosa decalvans. It will also discuss the neutrophilic and mixed primary cicatricial alopecias, namely folliculitis decalvans, dissecting cellulitis, folliculitis keloidalis, folliculitis (acne) necrotica, and erosive pustular dermatosis.

The Use of Anti-Keratin 903 Antibodies to Visualize Colloid Bodies and Diagnose Lichen Planopilaris

Cytokeratins are a major component of colloid bodies that are essentially diagnostic of lichen planopilaris (LPP). Here, the authors assess the ability of the cytokeratin 903 antibody (CK-903) to stain colloid bodies and differentiate LPP from other histologically similar appearing primary cicatricial alopecias. A retrospective review of all specimens submitted to the dermatopathology department over a 2-year window identified 18 cases of LPP and 20 cases of histologically similar appearing entities (discoid lupus erythematosus or central centrifugal cicatricial alopecia) through a combination of H&E, elastic van gieson, and periodic acid-schiff stains. All 38 samples were then prospectively stained with CK-903. Colloid bodies were identifiable in 3 of the 18 LPP cases based on H&E alone but were seen in 9 of 18 cases when CK-903 was used. There were no cases where colloid bodies were seen on H&E but not subsequently identified with CK-903. Additionally, there was no CK-903 staining in any of the 20 cases of similar appearing entities except 1 case of discoid lupus erythematosus, which is known to occasionally show colloid bodies. The authors conclude that CK-903 is a useful adjunctive tool that will allow for a quicker, less costly, and more accurate diagnosis of LPP given its ability identify colloid bodies even in the setting of significant inflammation and fibrosis and its advantages over direct immunofluorescence of low cost, short preparation time, and lack of need for a specialized fluorescent microscope.

Evaluation and Management of the Hair Loss Patient in the Primary Care Setting

Alopecias represent a heterogeneous group of disorders with different etiologies, presentations, and treatment options. The evaluation of the hair loss patient includes a comprehensive clinical history and physical examination; appropriate laboratory testing; and if indicated, a scalp biopsy. Treatment methods vary depending on the type of alopecia, and include watchful waiting, topical and systemic formulations, surgery, and treatment of any underlying or associated conditions. Referral to a dermatologist is helpful in diagnostically challenging and difficult to treat cases. Alopecia can cause emotional, mental, and social distress to patients. Early diagnosis and timely institution of appropriate treatment are helpful and comforting to those affected by this disease.

Evaluation and diagnosis of the hair loss patient: part I. History and clinical examination

Hair loss (alopecia) is a common problem and is often a major source of distress for patients. The differential diagnosis of alopecia includes both scarring and nonscarring alopecias. In addition, many hair shaft disorders can produce hair shaft fragility, resulting in different patterns of alopecia. Therefore, an organized and systematic approach is needed to accurately address patients' complaints to achieve the correct diagnosis. Part 1 of this 2-part continuing medical education article on alopecia describes history taking and the clinical examination of different hair loss disorders. It also provides an algorithmic diagnostic approach based on the most recent knowledge about different types of alopecia.

Hair morphology in androgenetic alopecia: sonographic and electron microscopic studies

OBJECTIVES

To assess hair morphology in androgenetic alopecia on sonography and electron microscopy.

METHODS

A prospective study was performed in 33 patients with androgenetic alopecia and 10 unaffected control participants. In vivo sonography of the hair follicles of the scalp and in vitro sonography and electron microscopy of the hair shafts were performed according to a standardized protocol that included analysis of the right frontal and occipital regions. The upper frequency limit of the ultrasound probes ranged between 15 and 18 MHz.

RESULTS

Scalp hair follicles and hair shafts were recognizable on sonography in all cases. Hair follicles in alopecia cases had significantly lower depths (P < .05). The hair shafts in alopecia also had a different distribution of their laminar pattern on in vitro sonography, with a greater presence of mixed (trilaminar and bilaminar) and solely bilaminar tracts in comparison with the controls (mostly trilaminar). On electron microscopy, the alopecia hair tracts showed irregularities and commonly a "melted candle" appearance of the cuticle.

CONCLUSIONS

Sonography and electron microscopy uncover distinct abnormalities in the morphology of hair in androgenetic alopecia, which may potentially support the diagnosis and management of this common condition.