95 citations
,
October 2007 in “International Journal of Dermatology” This study found that human hair can be classified into eight main types based on objective measurements of shape, rather than ethnic categories, enhancing the understanding of hair diversity globally.
17 citations
,
November 2013 in “Clinical and experimental dermatology” This case report describes repigmentation and curling of hair in a patient undergoing acitretin therapy.
16 citations
,
June 2017 in “PLoS ONE” This small study reports that a 6-group geometric classification method is more reliable for classifying human hair curl, although a digital system could further reduce errors.
14 citations
,
January 2006 in “Skinmed” A woman developed white patches on her skin and curly hair after hepatitis C treatment, likely due to the medication interferon alpha.
5 citations
,
January 2016 in “Clinical psychopharmacology and neuroscience/Clinical Psychopharmacology and Neuroscience” This report discusses that curly hair is a very rare side effect of valproate, a medication used as a mood stabilizer for bipolar disorder, though such drug-induced hair changes are uncommon.
1 citations
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October 2019 in “Epileptic disorders” In this case report, a 13-year-old girl with Pitt-Hopkins syndrome developed hair curling after starting the antiepileptic drug perampanel, which had not been previously reported as a side effect.
May 2023 in “Accounts of chemical research” This study aimed to identify new quantitative geometric and mechanical parameters for curly and kinky hair using various microscopy and mechanical analysis methods, revealing correlations between hair fiber geometry and mechanical performance to enhance personal care product development and promote cultural inclusion.
January 2006 in “Seibutsu Butsuri” Curly and straight hair differ in how their internal fibers are arranged.
19 citations
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October 2016 in “Journal of oncology pharmacy practice” In this study, the first case of a persistent curly hair phenotype was reported with nivolumab treatment in a patient with metastatic squamous cell lung cancer.
April 2026 in “Journal of Cosmetic Dermatology” This study reports that specific hair care practices common among individuals with high-curl-pattern hair could exacerbate seborrheic dermatitis, presenting significant treatment challenges and psychological impacts, and emphasizes the need for further research to tailor culturally sensitive solutions.
8 citations
,
December 2020 in “Scientific reports” This study examined the genetic basis for the curly hair trait in Mangalitza pigs, finding two specific genetic variants that contribute to this distinctive phenotype through autosomal dominant inheritance.
8 citations
,
July 2019 in “The journal of investigative dermatology/Journal of investigative dermatology” This study found that the tensile strength of curly hair is influenced by two main components, with springiness (toe region) contributing significantly, unlike in noncurly hair where it is negligible.
6 citations
,
October 2018 in “Drug safety - case reports” In this report, two women treated with alitretinoin experienced persistent curling of their previously straight hair, suggesting a likely causal link between the medication and hair texture changes.
January 2026 in “Biomedical and Biopharmaceutical Research” This study found that formulations containing pequi and buriti oils improved texture properties and significantly increased gloss in curly hair, with pequi oil also significantly enhancing tensile strength.
November 2024 in “Journal of Microscopy” This study found that micro-computed tomography (micro-CT) was highly effective for analyzing the cross-sectional geometry of hair fibres, including the medulla in highly curled hair, but less effective than scanning electron microscopy for surface details.
In this research, the author hypothesizes that curly hair is influenced by the contraction of the Arrector Pili muscle, suggesting that its relaxation through specific treatments could potentially modulate hair follicle curvature, but further studies are needed to confirm this mechanism.
January 2024 in “Indian Journal of Pharmaceutical Sciences” This study hypothesizes that the curling of hair may result from the contraction of the Arrector Pili Muscle, contributing to the diverse types of curly hair.
This study identified new geometric and mechanical parameters for curly and kinky/coily hair, which may inform more effective personal care products tailored to these hair types.
This study used quantitative methods to identify new geometric and mechanical parameters of curly and kinky/coily hair, aiming to improve classification and develop better personal care products for these hair types.
September 2015 in “The European physical journal. E, Soft matter and biological physics/The European physical journal. E, Soft matter” In this study, a mechanical model was developed to describe and validate the effectiveness of overnight hair curling, suggesting that combining it with hair fixatives can maintain a desired curl for over a day.
78 citations
,
June 2003 in “Journal of the American Academy of Dermatology” This article reviews the autonomous functioning and complex interactions within hair follicles, emphasizing their unique composition and differentiation pathways, but does not report new research findings.
13 citations
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November 2012 in “International Journal of Dermatology” This study of African-American women found that those perceiving greater hair breakage showed lower break stress and higher premature failure rates, linked to grooming practices and hair curvature.
13 citations
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March 2017 in “Skin Research and Technology” In this study, formaldehyde hair straighteners significantly damaged curly hair by reducing break stress and break extension, while glyoxylic acid had a milder effect; both treatments increased shear modulus and decreased water sorption.
12 citations
,
July 2015 in “British journal of dermatology/British journal of dermatology, Supplement” This study found that mechanical damage from grooming and environmental factors contributes to crack formation and eventual breakage in African-American hair, highlighting the need for continuous care.
8 citations
,
March 2014 in “Dermatologic Clinics” This article discusses surgical hair restoration for individuals with curly hair, emphasizing specific considerations and techniques required, but reports no new clinical results.
In this study conducted at Shafa Hospital, Kerman, Iran, 3.5% of patients using sodium valproate as an antiepileptic experienced hair loss and curling over ten years.
6 citations
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March 1986 in “PubMed” This case study describes a 19-year-old female patient who gained 13 kg and experienced hair changes while on valproic acid, and partially lost weight after reducing the dosage, but hair changes persisted.
3 citations
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November 2019 in “Clinical psychopharmacology and neuroscience/Clinical Psychopharmacology and Neuroscience” Valproate can cause both hair loss and curly hair in bipolar disorder patients.
1 citations
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July 2024 in “International Journal of Cosmetic Science” This study validated a new tool for assessing curly hair manageability, finding that hair curvature is a key factor influencing hair practices and product attitudes among women with natural curly hair.
January 2019 in “Pediatric Oncall” This article reviews the use of valproate in epilepsy treatment and its side effects, noting that hair texture changes such as curly hair are a rarely reported effect, but reports no new clinical results.