Concomitant manifestation of pili annulati and alopecia areata: coincidental rather than true association

The autosomal dominantly inherited hair disorder pili annulati is characterized by alternating light and dark bands of the hair shaft. Concomitant manifestation of pili annulati with alopecia areata has been reported previously on several occasions. However, no systematic evaluation of patients manifesting both diseases has been performed. We studied the simultaneous or sequential occurrence of pili annulati and alopecia areata in individuals diagnosed in different European academic dermatology units. We included 162 Caucasian individuals from 14 extended families, comprising 76 affected and 86 unaffected family members. Statistical analysis showed that the frequency of alopecia areata among patients with pili annulati was higher than within the general population. Five of our patients with pili annulati have gone through severe episodes of alopecia areata. We cannot rule out that the currently unknown genetic defect underlying pili annulati might also confer an increased risk for the development of a more pronounced manifestation of alopecia areata. Based on the current data, and considering the low number within individual families of patients affected by both diseases, however, a direct association between pili annulati and alopecia areata seems unlikely.     

Pili Annulati Coincident with Alopecia Areata

Abstract: Pili annulati is a rare hair shaft abnormality of unknown pathogenesis which gives a gross beading effect. An association with alopecia areata has been reported. We present a 13-year-old girl who had alopecia areata and coincidentally was found to have pili annulati. Her mother also had pili annulati which had become more noticeable as her hair had become paler with age. We discuss the possible pathogenesis of pili annulati and relate that to the microscopic banding appearance of the hair shaft. We note the relevance of the condition becoming more apparent with age. We also discuss the probable coincidental association with alopecia areata.     

Disappearance of pili annulati following an episode of alopecia areata

Pili annulati is a distinctive autosomal dominant hair shaft disorder that produces alternating light and dark bands that can give a spangled appearance to the hair. The literature contains three case reports of patients in whom the condition has disappeared following recovery from alopecia totalis. None of these reports contain a direct microscopic comparison of pre- and post-regrowth hairs. We report a 6-year-old girl who was first noted to have pili annulati at the age of 2 years and who developed alopecia totalis at the age of 3 years. When the hair regrew spontaneously, 18 months later, the pili annulati was no longer visible. Hair samples obtained before and after the episode of alopecia areata were compared by normal and cross-polarized light microscopy. While not apparent on careful clinical examination, banding was present on light microscopy in 20% of the hairs. Eighty per cent of the affected hairs displayed banding throughout their entire length. In contrast, prior to the episode of alopecia totalis, when the pili annulati was clearly visible, 50% of the hair obtained was banded on microscopy and 90% of the affected hairs showed banding throughout their microscopic length.     

Hair diagnoses and signs: the use of dermatoscopy

Background.  Hair-shaft examination is diagnostically useful in a range of adult and paediatric conditions.
Objective.  To evaluate the usefulness of dermatoscopy in hair-shaft microscopy.
Methods.  Typical examples of selected conditions from an extensive collection of scalp hair were examined using a dermatoscope and a light microscope with paired cross-polarizing filters. Hair-shaft characteristics were photographed using a digital camera.
Results.  Dermatoscopy was helpful in detecting tapered hairs, weathering, monilethrix, pediculosis capitis, peripilar casts, 'exclamation-mark' hairs of alopecia areata, bubble hair and pili torti. It was less helpful in pili annulati and unhelpful in detecting 'tiger-tail' banding in trichothiodystrophy. Light microscopy provided greater detail in almost all cases; it was necessary for detection of cuticle changes and added significant information in detecting characteristic features of trichothiodystrophy, pili annulati, bubble hair and pili torti.
Conclusions.  Dermatoscopy is most revealing in conditions resulting in gross changes in shaft outline and colour, where reflected light is valuable. It is unhelpful for detection of features within the shaft or at higher levels of resolution. When added to its ability to aid evaluation of scalp surface characteristics, dermatoscopy provides an excellent first-line method of assessment in clinics. In vivo it may aid screening and selection of hairs of greatest diagnostic yield for further assessment. In some instances, it may obviate the need for obtaining hair specimens and have implications for public health screening. Where detailed or cortical hair-shaft features need assessment, transmitted light microscopy remains the standard tool.     

Update on detection, morphology and fragility in pili annulati in three kindreds

BACKGROUND: Pili annulati is an inherited hair shaft abnormality with a wide range of clinical expression. OBJECTIVE: We have examined closely three kindreds to reveal levels and character of expression of the phenotype and supplement current literature on the threshold for detection and aspects of hair shaft fragility. PATIENTS AND METHODS: Eleven cases of pili annulati from three families were included in a clinical and morphological study. All cases were assessed clinically and by light and scanning electron microscopy (SEM) of hair shafts. In addition, transmission electron microscopy (TEM) (four patients) and amino acid analysis (three patients) were undertaken on clinically overt cases. Results Examination by light microscopy with a fluid mountant was more sensitive than clinical examination, increasing the detection rate by 120%. Microscopic examination revealed that the characteristic periodic bands become less frequent distally in the hair shaft. Microscopic features of weathering were found in two cases, adding pili annulati to the list of structural hair shaft dystrophies that may weaken hair and dispose to weathering. Amino acid analysis of the hair of three patients with pili annulati showed elevated lysine and decreased cystine content compared to 12 normal controls, consistent with the reduced threshold for weathering. CONCLUSION: Careful light microscopy with fluid-mounted hair is needed to detect subjects mildly affected by pili annulati. Expression of the phenotype varies widely between individuals, between hairs and within hairs of the same individual, where ageing of the hair diminishes detectable features.     

Cytokeratin expression in pili annulati hair follicles

Pili annulati is a rare autosomal inherited hair shaft abnormality of unknown pathogenesis in which clinical examination reveals alternating light and dark bands leading to a shiny appearance of the hair due to cavities within the cortex of the hair shaft. This is the first investigation of the proposed cytokeratin defect in pili annulati hair follicles. Four cryopreserved pili annulati and four control scalp specimens were analysed using immunohistochemistry for different 'hard' trichocytic and 'soft' epithelial cytokeratins including K1, K6, K10, K14, K16, K17, K18, K19, Ha1 and Hb1. There was no difference in staining intensity and quality of staining pattern seen in pili annulati and control scalp specimens. These results suggest that pili annulati is not caused by a defect of the cytokeratins investigated in this study.     

Pyoderma gangrenosum—an association with Hodgkin's disease

Pili annulati (ringed hair) is a rare hair anomaly characterized by alternating light and dark bands along the hair shaft. The light bands are due to air-filled cavities which scalier the light. It is inherited as an autusomal-dominant trait, although sporadic cases have been reported. The authors report the occurrence of three cases of piti annulati in a mother and two children. In both children, a buy and a girl 12 and IS years old, respectively, (he anomaly had been present since the first year of life. In the young girl, alopecia areata was also present from the age of 7; this unusual association seems to be fortuitous. The mother and one of her brothers were also affected less severely. All the patients clinically showed an increased brittleness of the hair that appeared otherwise normal. The nails and teeth were unaffected. Ammo-acid analysis of the hair was performed and showed low levels of serine and glycine and high levels of glutamic acid. The typical light, polarized and scanning-electron microscopy changes in the hair shaft are described. The inheritance of the disease is discussed.     

Alterations in the basement membrane zone in pili annulati hair follicles as demonstrated by electron microscopy and immunohistochemistry

BACKGROUND: Pili annulati is a rare autosomal dominant inherited hair shaft abnormality in which clinical examination reveals alternating light and dark bands leading to a shiny appearance of the hair. The clinically light bands are the abnormal areas due to cavities within the cortex. The pathogenesis remains unknown. OBJECTIVES: To investigate the expression of the basement membrane zone (BMZ) components in pili annulati hair follicles of the scalp. METHODS: Transmission electron microscopy (TEM) was carried out on scalp sections of six individuals with pili annulati and six controls. Longitudinal sections of scalp tissues from four individuals with pili annulati and six normal controls were studied by immunohistochemistry with a panel of monoclonal antibodies to the following BMZ components: alpha(6)beta(4) integrin, laminin 5, LH39 antigen, laminin 1, collagen IV and collagen VII. RESULTS: Using TEM, pili annulati scalp specimens exhibited a reduplicated lamina densa in the region of the root bulb in comparison with the single thin electron-dense band in controls. Using immunohistochemistry, there was a wavy BMZ in pili annulati follicles with antibodies to components of the lamina lucida, lamina densa and anchoring fibrils, whereas the BMZ in control hair follicles was as a smooth linear band. The expression of the hemidesmosome-associated alpha(6)beta(4) integrin was linear in both pili annulati and control hair follicles. CONCLUSIONS: Our results suggest that the genetic defect may be a mutation in proteins involved in signalling and regulation of formation and degradation of the lamina densa and sublamina densa region resulting in abnormal assembly or remodelling of the BMZ.     

Acquired hair fragility in pili anulati: causal relationship with androgenetic alopecia

Pili anulati are defined by characteristic alternating light and dark banding in the hair shaft, due to air-filled spaces between the macrofibrillar units of the hair cortex, and are regarded as a congenital hair shaft disorder without increased hair fragility. Two cases of pili anulati are presented, in which fragility of hair developed in a causal relationship with the onset of androgenetic alopecia. Accordingly, trichorrhexis-nodosa-like hair fracturing was exclusively limited to the androgenetic region. In general, secondary trichorrhexis nodosa is an unspecific finding related to excess stress of hair in relation to its fragility. With onset of hair thinning due to androgenetic alopecia, progressive reduction of hair shaft diameter may cause increased fragility in pili anulati. In this case, hair shaft fracturing occurs within the area of androgenetic alopecia and colocalizes with the air-filled cavities of pili anulati.     

Newly described weathering pattern in pili annulati hair shafts: a scanning electron microscopic study

Certain scalp hair shafts from 2 of 10 cases of pili annulati examined by scanning electron microscopy exhibited an unusual weathering pattern. The majority of affected hair shafts showed minor surface abnormalities at regular intervals (nodes) associated with the underlying spaces. However, in a few examples, there was marked damage to the cuticle at the nodes exposing the underlying cortex; in severe cases there was cracking of both cuticle and cortex. These damaged nodes were also associated with trichorrhexis nodosa-like breaks of the hair shaft. This study shows that the nodes in pili annulati may have some inherent weakness that could result in breaks in the hair shaft exposed to physical trauma.     

Dermoscopy for the Pediatric Dermatologist Part I: Dermoscopy of Pediatric Infectious and Inflammatory Skin Lesions and Hair Disorders

The dermoscope allows physicians to examine the macroscopic and microscopic primary morphology of skin lesions, identify subtle clinical clues, confirm naked‐eye clinical diagnoses, and monitor treatment progress while posing little threat to the young patient. This review summarizes important dermoscopic structures seen in infectious and inflammatory skin conditions and hair disorders in children. Scabies, pediculosis, phthiriasis, molluscum contagiosum, tinea nigra, and verrucae are well characterized dermoscopically by delta‐shaped structures, ovoid‐shaped nits, the crab louse, red corona, brown strands or spicules, and multiple densely packed papilla with a central black dot surrounded by a whitish halo, respectively. These dermoscopic structures will be discussed, focusing on the dermoscopic morphologies and dermoscopic sensitivity for diagnosis and its utility in monitoring treatment progress. Dermoscopy has also been shown to significantly improve the clinician's diagnostic and monitoring accuracy of inflammatory skin lesions such as psoriasis, which is characterized dermoscopically by uniformly distributed dotted blood vessels, and lichen planus, which is characterized by whitish lines on a purple to reddish background. Dermoscopy of the hair and scalp (trichoscopy) facilitates the differential diagnosis of hair diseases in children, including alopecia areata, trichotillomania, and tinea capitis. It can also assist in the diagnosis of multiple genetic hair shaft disorders, such as monilethrix, trichorrhexis invaginata, trichorrhexis nodosa, pili torti, and pili annulati.     

Prognosis and Management of Congenital Hair Shaft Disorders without Fragility—Part II

Hair shaft disorders are characterized by congenital or acquired abnormalities of the hair shaft. The objective of this study was to review the literature regarding the prognosis and treatment options for hair shaft disorders. We used keywords in the search engines PubMed and Medline to identify all publications in English related to the prognosis and management of hair shaft disorders. Data were extracted from 96 articles that met search criteria. Findings were limited to case reports and small case series, as no studies were found. Disorders that improve in childhood include pili torti, trichorrhexis invaginata, woolly hair, and pili trianguli et canaliculi. Others, such as trichorrhexis nodosa, monilethrix, pili annulati, and pili bifurcati, improve with minoxidil. Oral retinoids have been found to improve hair abnormalities in trichorrhexis invaginata and monilethrix. There is no specific treatment for congenital hair shaft abnormalities. Gentle hair care is the mainstay of care for hair shaft disorders associated with fragility. Practices for gentle care include no brushing, backcombing, chemical products, tight braids, heat exposure, or mechanical grooming. Furthermore, any inherited or congenital disorder requires genetic counseling as part of management.     

Prognosis and Management of Congenital Hair Shaft Disorders with Fragility—Part I

Hair shaft disorders are characterized by congenital or acquired abnormalities of the hair shaft. The objective was to review the literature regarding the prognosis and treatment options of hair shaft disorders. We used keywords in the search engines PubMed and Medline to identify all publications in the English language related to the prognosis and management of hair shaft disorders. Data were extracted from 96 articles that met search criteria. Findings were limited to case reports and small case series, as no studies were found. Disorders that improve in childhood include pili torti, trichorrhexis invaginata, wooly hair, and pili trianguli et canaliculi. Others, such as trichorrhexis nodosa, monilethrix, pili annulati, and pili bifurcati improve with minoxidil. Oral retinoids have improved hair abnormalities in trichorrhexis invaginata and monilethrix. There is no specific treatment for congenital hair shaft abnormalities. Gentle hair care is the mainstay of care for hair shaft disorders associated with fragility. Practices for gentle care include no brushing, backcombing, chemical products, tight braids, heat exposure, or mechanical grooming. Any inherited or congenital disorder requires genetic counseling as part of management.     

A gene locus responsible for the familial hair shaft abnormality pili annulati maps to chromosome 12q24.32-24.33

Pili annulati, a rare hair shaft abnormality with a characteristic shiny appearance due to alternating light and dark bands of the hair, is assumed to be inherited in an autosomal dominant mode with high penetrance. A locus for pili annulati has not been found yet. We identified one large and four small European kindreds with pili annulati and conducted a genomewide linkage analysis using 382 microsatellite markers. A multipoint logarithm of the odds (LOD) score of 3.19 was demonstrated between D12S1659 and D12S1723 on the telomeric part of the long arm of chromosome 12. Subsequent finemapping in a region of 20 cM gave a maximum multipoint LOD score of 3.24 at D12S1723 under the assumption of homogeneity and a LOD score of 3.57 around D12S343 under the assumption of heterogeneity, both exceed the statistical thresholds necessary to conclude linkage. Most of this LOD score came from the largest family, which reached a maximum LOD score of 3.81. The maximum two-point LOD score for all families was 3.97 at D12S1609. Definite recombination events narrowed the region of shared haplotype in the affected individuals to an 8 Mb region between the marker D12S324 and the telomeric end of the long arm of chromosome 12.     

Letter: Pili annulati - What about racial distribution?

Pili annulati is a rare hair shaft abnormality and, as far as we know, there are no published data on pili annulati's racial distribution. To our knowledge, this is the first case reported in an African-American patient.     

An optical study of human hair colour in normal and abnormal conditions.

The gross appearances of human scalp hair have been analysed according to the optical properties of individual hair fibres, the spectrophotometric features of hair in the mass, and the resolution of hair colour into its shade, dilution and luminance. It was found that apparent differences in colour were related more to luminance and dilution than to changes in the actual colour. Non-pigmentary factors such as the optical behaviour of the hair shaft, its structure, size and shape were probably more important than the pigment in determining its final appearance. Albinism, Chédiak-Higashi syndrome, kwashiorkor and pili annulati were specially consi dered.     

Quantitative image analysis of hair follicles in alopecia areata.

We took biopsies from similar sites on the scalps of normal controls, normal looking and hair loss areas of patients with alopecia areata. The specimens were sectioned serially and horizontally. We measured morphological parameters, such as the diameter of the hair shaft, the thickness of the inner root sheath, the diameter of the outer root sheath, the irregularity of the outer root sheath and the ratio between the diameters of the hair shaft and the outer root sheath, using a computerized image analysis system. There were significant differences in 5 parameters between hair loss areas and normal controls. The proportions of vellus and telogen hair were significantly higher in the areata areas than in the controls. The 5 morphological parameters and most quantitative-measured parameters of normal-looking areas from patients with alopecia values intermediate between the other groups.     

Hair loss: an overview

Hair loss is a common problem in men and women. Correct diagnosis of hair disorders is complex and requires evaluation of clinical presentation, history, physical examination, and laboratory tests. Hair loss may be categorized as hair shaft abnormalities, permanent alopecia, or nonpermanent alopecia. Nonpermanent alopecia, the most common type, includes androgenetic alopecia, telogen effluvium, alopecia areata, and traction alopecia. The hallmark of this group is the possibility of complete regrowth with adequate treatment.