[Pseudofolliculitis barbae in police students in Dakar: epidemiological and clinical aspects, and associated risk factors]. / Pseudo-folliculite de la barbe chez les élèves policiers à Dakar : aspects épidémio-cliniques et facteurs de risque associés.

Background: Pseudofolliculitis barbae (PFB) is a chronic inflammatory skin disease favoured by shaving. It is particularly common among black Africans belonging to certain socio-professional categories who are obliged to shave. Its aesthetic and professional damage is very significant. However, very few data are available for this condition, especially in Sub-Saharan Africa. Objective: To determine the epidemiological and clinical aspects, and the risk factors associated with the occurrence of PFB in Dakar. Population and methods: This was a descriptive cross-sectional study conducted in March 2019, including 655 police students at the National Police Academy in Dakar, all of African descent and with curly hair, who were required to shave weekly and agreed to participate in this study. The diagnosis of PFB was clinically based. Data analysis was processed using Epi-info version 6.0 software. Pearson's chi-square test was used for bivariate analysis with a significance threshold of p < 0.05. The Odds Ratio, with its 95% confidence interval, was used to determine the risk factors. Results: Among the 655 officers, 254 had PFB, with a prevalence of 38.8%. The prevalence of PFB was 43.7% in men (242 men out of 554) and 11.9% in women (12 women out of 101). The average age of patients with PFB was 26.80 years (± 2.59), ranging from 22 to 36 years. The age of onset of PFB was between 18 and 20 years for the majority (39.8%), with a mean age of onset of 22.2 years (± 3.6). PFB lesions were pruritic in 84.6% of cases, papular in 96.8%, and/or pustular in 60.2%. The submandibular region was the most affected site (69.8%). Complications were noted in 90.1% of cases in the form of post-inflammatory hyperpigmentation (87%) and keloid scars (3.1%). The risk factors associated with PFB were male sex (p<0.0001; OR=5.7; CI95% [3.07-10.75]), family history of PFB (p<0.0001; OR=5; CI95% [3.35-7.37]), keloid-prone skin (p<0.0001; OR=2.9; CI95% [1.63-4.96]), association with acne keloidalis nuchae (p<0.0001; OR=8.8; CI95% [5.55-14.08]), use of a single-blade razor (p<0.0001; OR=2.5; CI95% [1.69-3.70]), use of a fixed-head razor (p<0.0001; OR=1.8 CI95% [1.28-2.77]), shaving against the grain (p<0.0001; OR = 6.3; CI95%= [4.33-9.08]), non-use of shaving products (p = 0.009; OR = 1.5; CI95%= [1.06-2]) and waxing (p<0.004; OR=2.7; CI95% [1.33-5.77]). On the other hand, the use of clippers (p<0.0001; OR = 0.5 CI95% [0.33-0.65]), pre-shave products (p<0.0001; OR = 0.4 CI95% [0.29-0.61]) and the use of razors with movable heads (p<0.0009; OR = 0.2 CI95% [0.17-0.35]) were protective factors against PFB. Conclusion: Our study confirms the high incidence of PFB in this population of black men of African descent. A genetic abnormality revealed by shaving must be evoked in the occurrence of PFB. Further genetic and immunohistochemical studies would be needed to support this hypothesis.

Pilomatrixomas: 31 years of experience in population under and over 18 years of age.

BACKGROUND: Pilomatrixoma, also known as calcifying epithelioma of Malherbe, is a benign cutaneous neoplasm that demonstrates differentiation towards the matrix portion of hair follicles. It is the most common benign cutaneous neoplasm in childhood and youth, although it can occur at any age. With a general incidence ranging from 0.001% to 0.0031% of all cutaneous tumors. There is a slight predilection for females, with a female-to-male ratio of 1.15:1. METHODS: Observational, descriptive, retrospective, and cross-sectional study conducted using the electronic database of the dermatopathology department of Dr. Manuel Gea González General Hospital, from January 1992 to July 2023. Only cases with a histopathological diagnosis of pilomatrixoma, pilomatricoma, and Malherbe's calcifying epithelioma were included. RESULTS: A total of 200 pilomatrixomas were recorded in 177 patients. The tumor predominantly affected females in the pediatric age group, with an average age of 22.98 years in the studied population. The most common location was the head (periorbital region), followed by the upper extremities and trunk. Upon separating the population into pediatric and adult groups, 111 and 89 cases were identified, respectively. CONCLUSIONS: We present a detailed study on pilomatrixomas with a comprehensive overview of the demographic, clinical, and epidemiological characteristics of this benign cutaneous neoplasm. The results revealed robust statistical data highlighting the distribution by age, gender, topography, morphology, accompanying symptoms, and frequency of clinical differential diagnoses. This study significantly contributes to the existing knowledge of pilomatrixomas and serves as a valuable reference for future research and clinical practice.

INTRODUCCIÓN: El pilomatrixoma o epitelioma calcificado de Malherbe es una neoplasia cutánea benigna que muestra diferenciación hacia la porción de la matriz de los folículos pilosos. Es la neoplasia cutánea benigna más frecuente en la infancia y la juventud, aunque puede ocurrir a cualquier edad. Tiene una incidencia general que oscila entre el 0.001% y el 0.0031% de todos los tumores cutáneos. Se reporta una ligera predilección por el sexo femenino, con una relación mujer: hombre de 1.15:1. MÉTODOS: Estudio observacional, descriptivo, retrospectivo y transversal en el que se utilizó la base de datos electrónica del departamento de dermatopatología del Hospital General Dr. Manuel Gea González, entre enero de 1992 y julio de 2023. Para la búsqueda de los casos solo se incluyeron aquellos con diagnóstico histopatológico de pilomatrixoma, pilomatricoma o epitelioma calcificado de Malherbe. RESULTADOS: Se registraron 200 pilomatrixomas en 177 pacientes. El tumor predominó en mujeres de edad pediátrica; el promedio de edad de la población estudiada fue 22.98 años. La topografía más frecuente fue la cabeza (región periorbitaria), seguida de las extremidades superiores y el tronco. Al separar la población en pediátricos y adultos, se encontraron 111 y 89 casos, respectivamente. CONCLUSIONES: Presentamos un estudio detallado sobre pilomatrixomas con una visión exhaustiva de las características demográficas, clínicas y epidemiológicas de esta neoplasia cutánea benigna. Los resultados revelaron datos estadísticos sólidos, destacando la distribución por edades, sexo, topografía, morfología, síntomas acompañantes y frecuencia de diagnósticos diferenciales clínicos. Este estudio contribuye significativamente al conocimiento existente sobre los pilomatrixomas y sirve como una referencia valiosa para futuras investigaciones y para la práctica clínica.

Changing spectrum of hair and scalp disorders over the last decade in a tertiary medical centre.

BACKGROUND: Hair- and scalp-related disorders (HSRDs) encompass a wide range of conditions that affect people of all ages. OBJECTIVE: To evaluate the workload and trends in HSRDs at an outpatient dermatological clinic in a tertiary medical centre over a 10-year period. METHODS: Medical records for HSRD visits to the outpatient dermatology clinic at the Sheba Medical Center, an Israeli tertiary care center, were reviewed between 1 January, 2010 and 31 December, 2020. RESULTS: There were 10,396 HSRD visits with a new-to-follow-up visit ratio of 1:1.9. The annual number of HSRD visits, as well as their proportion out of all dermatological outpatient visits, have increased from 295 (1.24%) in 2010 to 1726 (9.44%) in 2020. The patients' mean age was 35.3 years (women 39.5 years, men 28.8 years), age range 1-87 years. Over the decade, there was a growing predominance of women with an average female-to-male ratio of 2:1. The winter season accounted for 28.7% of annual visits, followed by the autumn (25.6%), summer (24.3%) and spring (21.4%). The most prevalent HSRDs included androgenetic alopecia (30.6%), alopecia areata (19.3%), telogen effluvium (15.4%), non-scarring folliculitis (15.4%), seborrheic dermatitis (14.9%), lichen planopilaris (7.1%) and folliculitis decalvans (6.6%). Androgenetic alopecia demonstrated the highest increase over the decade examined (from 17% to 32%). CONCLUSION: HSRDs account for a significant percentage of visits at a tertiary dermatology outpatient clinic. The number of HSRD visits has increased annually over the past decade. The recent advancement in diagnosis and treatment may account, at least in part, for the growing burden of HSRDs within dermatological ambulatory care.

Patient Recovery from COVID-19 Infections: Follow-Up of Hair, Nail, and Cutaneous Manifestations.

BACKGROUND: COVID-19 is a pandemic disease worldwide. Although cutaneous manifestations may present in affected patients, there have been limited studies on the cutaneous findings and hair and nail abnormalities after discharge. OBJECTIVE: To establish the cutaneous manifestations, hair and scalp disorders, and nail abnormalities in patients who recovered from COVID-19 infections. METHODS: A retrospective chart review and telephone interviews were conducted to determine the cutaneous manifestations, hair and scalp disorders, and nail abnormalities of patients aged over 18 years who were diagnosed with COVID-19 infections at Siriraj Hospital, Bangkok, Thailand, between January and June 2020. RESULTS: Ninety-three patients with prior COVID-19 infections participated in the study. The COVID-19 severity had been mild for most (71%). Cutaneous manifestations were reported in 8 patients (8.6%), with the common skin conditions being maculopapular rash and urticaria. The onsets of the skin conditions were before admission (1%), during admission (4.3%), and after discharge (3.2%). Increased hair shedding was also reported in 22 patients (23.7%), with a female predominance. Three patients were affected during admission, while the others were affected after discharge. The patients with moderate, severe, and critical COVID-19 infections experienced significantly more hair shedding than those with asymptomatic and mild diseases. Only 2 patients with mild COVID-19 disease reported nail abnormalities (chromonychia and brittle nails). CONCLUSIONS: Cutaneous manifestations, hair disorders, and nail abnormalities can occur in patients with COVID-19 after their discharge from hospital. Patients should therefore be followed up in anticipation of dermatological problems.

Premature graying of hair: Risk factors, co-morbid conditions, pharmacotherapy and reversal-A systematic review and meta-analysis.

Premature graying of hair (PGH) being a very common entity for which pharmacotherapy and reversibility are not properly addressed. Therefore, this systematic review was conducted to address these issues. For this relevant study were selected from various databases including PubMed, EMBASE, OVID, Web of science, Scopus, and Google Scholar till January 20, 2019. Studies which reported risk factors, co-morbid conditions associated with PGH, its pharmacotherapy and reversal were included in the study. Although many risk factors are reported in literature, smoking, vitamin deficiency (B12, folic acid, and B7), mineral deficiency (low serum calcium and serum ferritin) are found to be associated with PGH. Other important risk factors are family history of PGH, obesity, high B.P, lack of exercise, drugs, genetic syndromes, dyslipidemia, thyroid disorders, hyperuricemia, and alteration in liver function. PGH is found to be an important marker of CAD, more so in case of smoker. Among different pharmacotherapeutic management options, low grade recommendation (2A) is given to calcium pantothenate, PABA, calcium pantothenate + PABA combination. Anu-tailam is the only herbal agent evaluated in clinical research settings. Finally, treating the accompanying pathologies led to the reversal of the disease in many cases.

Striae Gravidarum, Acne, Facial Spots, and Hair Disorders: Risk Factors in a Study with 1284 Puerperal Patients.

OBJECTIVE: To determine the prevalence of skin changes during pregnancy and to relate their occurrence to specific factors in a population of south Brazil. METHODS: A cross-sectional analytical study was carried out with 1284 puerperal patients. A questionnaire about skin changes during pregnancy was developed and applied by the authors to all puerperal women admitted in a tertiary hospital in south Brazil. RESULTS: The appearance of striae during pregnancy was reported by 633 women (49.5%) and had a statistically significant association with primiparity, presence of stretch marks before pregnancy, and gestational weight gain above 21 kg. Facial blemishes were reported by 33.9% (n = 434) and were associated with a positive family history, multiparity, and the use of facial sunscreen (p < 0.0001). The onset or worsening of acne was identified in 35.7% (n = 456) and was statistically associated with primiparity and Fitzpatrick phototypes IV and V. Hair alterations were reported by 44.5% (n = 569) and were associated with primiparity (p = 0.029). CONCLUSION: Although most of the skin changes during pregnancy are considered "physiologic," they can cause significant discomfort. Thus, it is important to know them and to understand which risk factors may be associated with such changes.

Pilomatrixomas in children: Report of 149 cases. A retrospective study at two children's hospitals. / Pilomatrixomas en niños: a propósito de 149 casos. Estudio retrospectivo en dos centros pediátricos.

A pilomatrixoma is a benign skin tumor common in children, which develops from the matrix cells of hair follicles. It presents as a nodule or tumor of approximately 0.5-3 cm in size, with calcium-like consistency, faceted edges, and blue erythematous overlying skin. Sometimes, the skin may atrophy and look like a blister or even extrude calcium. Diagnosis is suspected based on the typical clinical presentation and supplementary imaging tests. The definite diagnosis is made according to histological findings. Surgical removal is the treatment of choice. Here we describe the epidemiological and clinical data, supplementary tests, and surgical techniques in relation to 149 pilomatrixomas resected in 137 patients treated at the Departments of Dermatology of two children's hospitals: Dr. Pedro de Elizalde and Prof. Dr. Juan P. Garrahan.

El pilomatrixoma es un tumor benigno cutáneo, de frecuente aparición en los niños, que se origina en las células de la matriz del folículo piloso. Se presenta como un nódulo o tumor, aproximadamente, de 0,5 a 3 cm de tamaño, de consistencia cálcica, de bordes facetados, con piel suprayacente eritematoazulada. En ocasiones, la piel puede atrofiarse, dar la apariencia de una ampolla e, incluso, extruir material cálcico. El diagnóstico se sospecha por la presentación clínica característica y los estudios de imágenes complementarios. El diagnóstico definitivo es por los hallazgos histológicos. La extirpación quirúrgica es el tratamiento de elección. Se presentan los datos epidemiológicos, clínicos, estudios complementarios y técnicas quirúrgicas empleadas de 149 pilomatrixomas resecados en 137 pacientes tratados en los Servicios de Dermatología de los hospitales de pediatría Dr. Pedro de Elizalde y Prof. Dr. Juan P. Garrahan.

Pseudofolliculitis Barbae: A Review of Current Treatment Options

The purpose of this review is to discuss the disease process and wide variety of treatment options for psuedofolliculitis barbae (PFB), or razor bumps. PFB is caused by hair follicles penetrating the skin and causing an inflammatory response. PFB can occur to anyone who shaves, and is more likely in those with curly hair. PFB can cause significant hyperpigmentation and scarring, more noticeable in darker skin types. PFB can be treated with a variety of topical, systemic, or light/laser therapies. Minimal progress has been made in treating PFB in recent years, partially due to the success of well-established current treatments discussed in this review. The most effective treatments involve a multifaceted approach including behavioral changes in shaving habits as well as the use of topical therapies. J Drugs Dermatol. 2019;18(3):246-250.

Hair manifestations of endocrine diseases: A brief review.

Hair disorders are common in clinical practice and depending upon social and ethnic norms, it can cause significant psychosocial distress. Hair growth, cycling and density are regulated by many endogenous factors, mainly circulating hormones. Thus, diseases affecting the endocrine system can cause varied changes in physiological hair growth and cycling. Diagnosis and treatment of these disorders require a multidisciplinary approach involving a dermatologist, gynecologist and an endocrinologist. In this review, we briefly discuss the influence of hormones on the hair cycle and hair changes in various endocrine disorders.

Updated view on epidemiology and clinical aspects of pilomatricoma in adults.

BACKGROUND: Clinically, pilomatricoma offers potential for a wide spectrum of differential diagnoses. It typically occurs in pediatric patients with the head being the most common location. A second peak of clinical presentation occurs in adults at age 50-65 years, suggesting a bimodal pattern of occurrence. OBJECTIVE: To investigate the clinical and epidemiological features of pilomatricoma in adults over 20 years old, as it is a common and frequently misdiagnosed tumor. METHODS: This was a retrospective study of pilomatricomas surgically removed at a tertiary hospital between January 1994 and December 2014. A search of the all-pathological database of patients aged over 20 years old with a pathological diagnosis of pilomatricoma was carried out. RESULTS: The clinical preoperative diagnosis of pilomatricoma was made in 34.0% of cases. Tumor location showed a predilection to the head and neck. Of the reported concomitant neoplasm, a majority had accompanying skin tumors. CONCLUSION: We conclude that clinical features in adults were similar to those of children. This study outlines clinical presentations that should help to guide differential diagnoses. Additionally, because of similarities between the distribution and depth of vellus hair follicles and pilomatricomas, it is probable that vellus hair bulbs may be the origin of this tumor.

Acne keloidalis nuchae: risk factors and associated disorders - a retrospective study.

BACKGROUND: Acne keloidalis nuchae (AKN) is a chronic scarring folliculitis which usually occurs in young adult males of African descent. Studies have suggested that AKN may be associated with other dermatologic conditions and even general medical disorders. The aim of this study was to identify cutaneous and extracutaneous associated disorders and to examine risk factors in our population for developing AKN. METHODS: The study was a retrospective, descriptive, and analytical study conducted at the Dermatology Outpatient department of the University Hospital of the West Indies. Data were obtained from the medical records of patients diagnosed over a 15-year period (2000-2014). RESULTS: There were 1031 new patients during the study period. Of these, 43 (4.2%) had AKN. The male to female ratio for AKN was approximately 7:1. Pseudofolliculitis barbae was associated with keloidal plaques on the scalp (OR = 6.22, P = 0.036). Also, when the duration of AKN was divided into two groups (0-5 years and greater than 5 years), there was an association between keloidal plaques and duration of greater than 5 years (OR = 7.5, P = 0.032). However, when the odds ratio was adjusted, only the duration of AKN remained significantly associated with keloidal plaques (OR = 7.08, P = 0.047). Chronic scalp folliculitis (P = 0.001) and the presence of any component disease of the metabolic syndrome (OR = 14, P = 0.008) and specifically hypertension (OR = 6.75, P = 0.036) were significantly associated with the extension of the lesions beyond the nape and occipital scalp. CONCLUSIONS: Pseudofolliculitis barbae, chronic scalp folliculitis, and aspects of the metabolic syndrome may be associated with acne keloidalis nuchae.

Dermatological diseases in palliative care patients: a prospective study of 271 patients.

BACKGROUND: Numerous risk factors place palliative care patients at an increased risk of skin infections, dermatitis, and pressure sores. Furthermore, worsening of chronic skin disorders can be expected, as well as the development of treatment-induced and malignancy-related dermatoses. The objective of the present study was to investigate the prevalence and treatment of dermatological conditions in patients receiving hospital-based palliative care. METHODS: Two hundred seventy-one palliative patients were enrolled. All assessments were conducted by dermatologists. Skin lesions were classified into seven categories: infections, skin tumors, dermatitis, chronic wounds, nail and hair disorders, pruritus, and other unclassified conditions. Treatment modalities were classified as topical only or systemic. RESULTS: Overall, 1,267 dermatological conditions were recorded, 49 % of which were hospital-acquired. All patients had at least one dermatological condition, and more than 50 different dermatological disorders were noted. The most common group of skin disorders was dermatitis (18.3 % of all dermatological conditions), followed by nail and hair disorders (17.5 %). Almost 16 % of dermatological conditions were treated systemically. CONCLUSIONS: Dermatological conditions are a common and clinically significant problem for palliative patients. The inclusion of dermatologists in multidisciplinary palliative teams should prove helpful in the management of these patients.

[Malignant cutaneous adnexal neoplasms of the face and scalp: Diagnostic and therapeutic update]. / Les tumeurs cutanées malignes à différentiation pilaire de la face et du cuir chevelu : mise au point diagnostique et thérapeutique.

INTRODUCTION: Malignant cutaneous adnexal neoplasms are rare and have been characterized only recently. They can occur at any age but preferentially in elderly. There are 3 of them: trichoblastic carcinoma, trichilemmal carcinoma and malignant pilomatricoma. The aim of our study was to make a diagnostic and therapeutic update about these tumors when located at the face or at the scalp. MATERIALS AND METHODS: A bibliographic research was made on PubMed using following keywords: appendage skin carcinoma AND pathology AND/OR therapeutic. Articles published before 2000 were considered outdated and were excluded. RESULTS: Twenty-five articles met the inclusion criteria. Clinical presentation was non-specific. Histological examination only allowed for diagnosis. Lesions were locally or loco-regionally aggressive. Lymphatic or hematogenous metastasis were reported. No consensus about treatment was found. When surgery was used, it consisted in resection with safety margins ranging from 0.5 to 3cm depending on the teams. In case of metastasis, treatment consisted in chemo- and/or radiotherapy. A quarterly medical monitoring was recommended. DISCUSSION: Malignant cutaneous adnexal tumors are rare. There is nowadays no treatment consensus. An initial staging by mean of a head and neck, chest, abdominal and pelvic CT-scan is mandatory. Treatment has to be decided in a multidisciplinary cancer committee. In the absence of metastasis, the reference treatment is surgical resection, possibly by Mohs micrographic technique, with large safety margins. In case of metastasis or if the loco-regional extension does not allow for a complete excision, chemotherapy and/or radiotherapy may be proposed. A close monitoring is essential.

Effects of age of onset on disease characteristics in non-segmental vitiligo.

In patients with vitiligo, the clinical and laboratory features of the disease may vary according to time of onset. This is addressed in the literature by only a few studies with conflicting results. The aim of this study was to determine the demographic and clinical features of patients with non-segmental vitiligo and to establish the association between vitiligo and autoimmune diseases with a focus on time of disease onset. A total of 224 vitiligo patients for whom complete medical records were available were evaluated retrospectively. Demographic data, scores on the Vitiligo Area Score Index (VASI), clinical features, vitiligo disease activity, repigmentation status, presence of any accompanying autoimmune disease, antinuclear antibody (ANA) titers, serum levels of glucose, thyroid-stimulating hormone (TSH), thyroxine (T4) hormone, anti-thyroid peroxidase (anti-TPO), and anti-thyroglobulin (anti-TG) were recorded. The prevalence of halo nevi was significantly higher (P < 0.001) among children than in other patient groups. The prevalence of leukotrichia was higher in adults with adult-onset disease than in either pediatric patients or adults with childhood-onset disease (P = 0.002). Both anti-TG and anti-TPO levels were significantly higher in adults with adult-onset disease than in pediatric patients and adult patients with childhood-onset disease. The prevalence of autoimmune disease was 22.2%. Anti-TG levels were significantly higher in patients with treatment-related repigmentation than in those without repigmentation. This study shows that clinical features and associations with autoimmune disease may vary according to the age of onset of vitiligo.

The Effect of Demodex Infestation on Blepharitis and the Ocular Symptoms.

OBJECTIVE: This study aimed to determine the frequency of Demodex infestation of eyelashes in patients with and without blepharitis and to determine the effects of Demodex infestation on blepharitis and the ocular symptoms. METHODS: The study included patients with chronic mixed (anterior + posterior) blepharitis who presented to our clinic. Patients with refractive error and no ocular disease were enrolled as the control group. From each participant, a total of 4 eyelashes were removed and were then examined under a light microscope for Demodex infestation. Symptoms, fluorescein tear breakup time, and ocular surface staining pattern were recorded. RESULTS: The prevalence of Demodex infection in the blepharitis group was 67.2%, versus 54.9% in the control group (P=0.18). The incidence of itching in the blepharitis group was significantly higher in the Demodex (+) patients than in the Demodex (-) patients (P<0.001). Fluorescein tear breakup time in the Demodex (+) patients was significantly shorter than in the Demodex (-) patients (P<0.001). There was not a significant difference in the fluorescein staining pattern between the 2 groups (P=0.57). The incidence of advanced stage blepharitis was significantly higher among the Demodex (+) patients (P=0.007). The incidence of cylindrical eyelash dandruff in the blepharitis group was significantly higher in the Demodex (+) patients (P<0.001). There was a significant difference in meibomian gland dysfunction between the 2 groups (P=0.039). CONCLUSION: Demodex infestation must be investigated in patients with advanced stage blepharitis, itching, and shorter than normal fluorescein tear breakup time.

Clinical and pathological features of hair coat abnormalities in curly coated retrievers from UK and Sweden.

OBJECTIVES: To gain information on hair loss amongst curly coated retrievers by questionnaire and to define the clinical and pathological features of hair coat abnormalities in affected dogs in the United Kingdom and Sweden. MATERIALS AND METHODS: Questionnaires were completed by members of the Curly Coated Retriever Clubs. Fourteen dogs (six in the United Kingdom, eight in Sweden) were clinically examined and skin/hair samples collected for microscopy and histopathology. Blood was collected for haematological, biochemical and endocrine assays. RESULTS: Of 90 dogs surveyed, 39 had current or previous episodes of symmetrical, non-pruritic alopecia and or frizzy coat changes, usually affecting caudal thighs, axillae, dorsum and neck before 18 months of age; 23 dogs had a waxing/waning course. Examined dogs generally matched the pattern described in questionnaires. Hair shaft anomalies comprised occasional distorted anagen bulbs (10 dogs) and transverse fractures (8 dogs). Vertical histopathological sections showed infundibular hyperkeratosis (28 of 30 sections) and low-grade pigment clumping (17 of 30). Subtle telogenisation of hair follicles was unequivocally confirmed by transverse histomorphometric analyses. CLINICAL SIGNIFICANCE: The follicular dysplasia of curly coated retriever reported here is similar to that of Irish water spaniels and Chesapeake Bay retrievers but distinct from that of Portuguese water dogs. The genetic basis requires further assessment.