Avaliação das propriedades das fibras capilares tratadas com alisante ácido com diferentes valores de pH / Evaluation of hair fibers properties treated with acid straightener at different pH values

Os produtos para alisamento das fibras capilares são amplamente utilizados no Brasil principalmente, pelo público feminino. Porém, estes procedimentos podem causar danos ao cabelo do usuário e, também, para o profissional que está atuando. Os alisantes químicos podem ser divididos em dois grupos: alcalinos e ácidos. Os primeiros (tioglicolato de amônio e os hidróxidos de sódio ou guanidina) apresentam valor de pH elevado (superior a 9,0) e alisam por meio da quebra e reorganização das pontes de dissulfeto (S-S) presentes na queratina, proteína estrutural da fibra capilar. Os alisantes ácidos como o formaldeído, ácido glioxílico e seus associados, possuem pH baixo (≥ 2,0) e causam uma reorganização no interior da fibra e geralmente leva a formação de um filme na superfície do fio. O ácido glioxílico associado à carbocisteína e aminoácidos (nomenclatura INCI -International Nomenclature of Cosmetic Ingredient apresentada entre parênteses) (Glyoxyloyl Carbocysteine (and) Glyoxyloyl Keratin Aminoacids (and) Water) é o único ingrediente permitido ao uso como alisante ácido até o momento. O objetivo deste trabalho foi estudar o efeito deste alisante ácido incorporado em uma emulsão óleo e água (O/A) com valores de pH 1,0 e 2,0 (com reaplicações); e o impacto que podem causar nas propriedades mecânicas e químicas da fibra capilar, como força de ruptura, coloração, elasticidade e teor de triptofano da fibra capilar. E também o efeito da radiação ultravioleta nos fios alisados. Nos testes realizados observou-se que as mechas tratadas com a emulsão a pH 1,0 obtiveram melhor resultado de alinhamento das cutículas e capacidade alisante da fibra, com penteabilidade superior ao cabelo virgem (59,4 %), enquanto as mechas com a formulação pH 2,0 foi apenas 33,0%. Entretanto, a força de tração para a ruptura do fio foi inferior, diminuindo em 16,0% (pH 1,0) e 9,0 % (pH 2,0). Quanto a variação da coloração, a variação do tom de cor foi mais exacerbada para as mechas tratadas com a formulação em pH 1,0. O teor de triptofano foi inferior nas mechas alisadas com a formulação pH 1,0. Para o teste de DSC e Raman, ambas as mechas tratadas apresentaram modificações nas suas estruturas. As fibras alisadas e expostas à radiação UV apresentaram danos maiores nas cutículas, e certa proteção na degradação de proteínas em relação aquelas sem tratamento e irradiadas ao UV. Considerando as reaplicações do produto alisante ácido, quanto maior o número de aplicações, mais alinhadas e seladas tornaram se as fibras, mas mais rígida e suscetível à quebra ficaram. Devemos considerar a importância do valor do pH da formulação no impacto do alisamento e dano da fibra capilar

Hair straightening products are widely used in Brazil by the female public. However, these procedures can cause damage to the hair shaft and to professional´s and client´s health. Chemical straighteners can be divided into two groups: alkaline and acid. Alkaline straighteners has a very high pH value (> 9.0) and the straightening process is due to the break followed by reorganization of the disulfide bridges (S-S) present in the keratin, a structural protein of the hair shaft. Some examples of alkaline straighteners are ammonium thioglycolate and sodium or guanidine hydroxides. On the other hand, acid straighteners like formaldehyde, glyoxylic acid, and their associated, present a low pH value (≥ 2.0), which causes a rearranging within the fiber, and sometimes creates a film on the surface of the hair. Nowadays, the glyoxylic acid associated with carbocysteine and amino acids (INCI - International Nomenclature of Cosmetic Ingredient nomenclature presented in parentheses) (Glyoxyloyl Carbocysteine (and) Glyoxyloyl Keratin Aminoacids (and) Water) is the only acid straightener permitted. Therefore, the objective of this work is to study the effect of this acid straightener, incorporated into oil in water (o/w) base emulsions at two different pH values 1.0 and 2.0 ( with reapplication) on the mechanical and physicochemical properties of the hair shaft. Also, the impact of UV radiation in straightened tresses. In the experiments conducted, it was possible to observe that tresses treated with the emulsion at pH 1.0 had a better result on the alignment and the straightening capacity, improving the combing test (59.4%/), while the tresses with the formulation at pH 2.0, 33.0%. However, the tensile strength, to pH 1.0 decreased by 16.0% and to pH 2.0 only 9.0%. As for color, the difference when compared with virgin hair it was major at pH 1.0. The tryptophan content also was lower in tresses treated at pH 1, 0. For the DSC and Raman analyzes all the treated tresses presented modifications in their structure. Straightened strands exposed to radiation had major damage in the cuticles, and some protection in proteins degradation compared to untreated tresses exposed to radiation. Considering the reapplications of the straightening product, as higher the number of applications more aligned and sealed it becomes, however the hair fiber becomes stiffer and susceptible to breakage. Thats why we should consider the importance of the pH value in the product, and the impact of straightening and damage of the hai fiber

Benign follicular tumors

Abstract: Benign follicular tumors comprise a large and heterogeneous group of neoplasms that share a common histogenesis and display morphological features resembling one or several portions of the normal hair follicle, or recapitulate part of its embryological development. Most cases present it as clinically nondescript single lesions and essentially of dermatological relevance. Occasionally, however, these lesions be multiple and represent a cutaneous marker of complex syndromes associated with an increased risk of visceral neoplasms. In this article, the authors present the microscopic structure of the normal hair follicle as a basis to understand the type and level of differentiation of the various follicular tumors. The main clinicopathological features and differential diagnosis of benign follicular tumors are then discussed, including dilated pore of Winer, pilar sheath acanthoma, trichoadenoma, trichilemmoma, infundibuloma, proliferating trichilemmal cyst/tumor, trichoblastoma and its variants, pilomatricoma, trichodiscoma/fibrofolliculoma, neurofollicular hamartoma and trichofolliculoma. In addition, the main syndromes presenting with multiple follicular tumors are also discussed, namely Cowden, Birt-Hogg-Dubé, Rombo and Bazex-Dupré-Christol syndromes, as well as multiple tumors of follicular infundibulum (infundibulomatosis) and multiple trichoepitheliomas. Although the diagnosis of follicular tumors relies on histological examination, we highlight the importance of their knowledge for the clinician, especially when in presence of patients with multiple lesions that may be the cutaneous marker of a cancer-prone syndrome. The dermatologist is therefore in a privileged position to recognize these lesions, which is extremely important to provide further propedeutic, appropriate referral and genetic counseling for these patients.

Cabello crespo adquirido progresivo: una tricogrifosis adquirida / Acquired progressive unruly hair: an acquired trichogriphosis

Se presenta un caso de cabello crespo adquirido progresivo. Se corrobora la presencia de los pili canaliculati y la disminución de la velocidad de crecimiento del pelo en las zonas afectadas. Se ubica a la afección entre otras relacionadas y se sugiere la posibilidad de denominarlas en común: tricogrifosis