Abstract Background: Neomycin is used in several over-the-counter pharmaceutical formulations in Brazil. In Europe and Canada, where it is not freely available, its sensitization frequency is lower than in the United States, where this does not occur. Objective: To present the frequency of sensitization to neomycin observed in a tertiary hospital and the pharmaceutical formulations sold in Brazil containing neomycin. Method: Retrospective analysis of positive results to neomycin, obtained through patch tests performed in a tertiary hospital, from 2009 to 2018 and investigation of topical drugs and vaccines containing neomycin in Brazilian databases available on the internet. Results: Among 1,162 patients, 71 (6%) had positive reactions to neomycin, 65% female and 35% male individuals, 46% were over 50 years old, and 24% had a personal history of atopy. The dermatitis lasted from four months to 20 years. Lesions were located in 69% of the patients on the upper limbs, in 55% they were on the lower limbs, and in 42% they were disseminated in more than 4 sites. Polysensitization was detected in 55% of cases. Of these, 28% were linked to sensitization to rubber allergens and 27% to potassium bichromate. A total of 158 topical presentations of neomycin were found: 79 ointments, 58 creams, 10 ophthalmic solutions, seven otological solutions, one oral solution, two nasal solutions, and one antiseptic powder, in addition to 11 types of vaccines. Study limitations: Retrospective study. Conclusion: Sensitization to neomycin occurred in 6% of the studied population, affecting more females aged over 50 years, with skin lesions located mainly on the upper and lower limbs, in the context of chronic contact dermatitis. Neomycin was found in 135 formulations, most of them available over the counter, as well as in 11 miscellaneous vaccines.

Abstract Five cases of telogen effluvium undergoing resolution are shown, with the presence of frontal, bitemporal, and occipital hair regrowth. Diagnosing acute telogen effluvium after the end of the active phase can be challenging, especially when the pull test is negative. The differential diagnosis includes alopecia areata and traction alopecia. Clinical signs of hair regrowth after telogen effluvium can help in the diagnosis. The frontal and temporal areas have more telogen hairs and are more affected. On the occipital area, hairs seem to have the same behavior. The acute telogen effluvium triad during resolution is proposed: frontal fringe, temporal recess and occipital fringe.

Abstract: Trichothiodystrophy refers to a heterogeneous group of rare genetic diseases that affects neuroectodermal-derived tissues with multisystem involvement. The hallmark of these syndromes is the deficiency of sulfur in hair matrix proteins, leading to short and brittle hair. Few cases of this rare disorder have been published. The authors report a case of trichothiodystrophy in a male infant with ichthyosis, photosensitivity, spastic paraparesis, short stature, and neurologic and psychomotor retardation. Diagnosis was based on clinical and microscopic features of hair samples.

Abstract: Behçet's disease is a systemic vasculitis characterized by attacks of acute inflammation, which can affect almost every vascularized area of the body. There is a close correlation between the geographical distribution of HLA-B51 and its prevalence. In the etiopathogenesis there are indications of genetic susceptibility associated with environmental influence. Among the involved genes are those that encompass innate and adaptive immunities. Polymorphisms and epistatic interactions in several genes are described, as well as the presence of imbalance lineage between HLA-B51 and A (MICA). Herpes simplex and Streptococcus sanguinis may be important extrinsic factors. An increase of Th1 response and of IL-21 is observed. The production of IL-21 is positively related to Th17 cells and negatively to T-regs. The mucocutaneous manifestations are Behcet´s disease markers, and their earlier onset indicates a worse prognosis. Recurrent oral ulcers have varied sizes and arrangements, genital ulcers are recurrent, leaving scars, skin lesions are multivaried, and pathergy, although not so frequent, is important for the diagnosis. There are numerous attempts to validate indexes that can evaluate the disease activity and among them the Mucocutaneous Activity Index. This is a specific score that can help with therapeutic decisions and to reduce morbidity, but still lacks validation. The clinical manifestations of other organs are described as well as treatment options.

Abstract: In Brazil there is no classification of dermatological products by the presence of vehicles with sensitizing potential. The objective of this study is to create a database to classify such products based on the absence of the selected allergens, aiming at making it available for medical consultation. We conducted an observational study, from the content of labels and/or inserts on the composition of 966 dermatological products in the Brazilian market. No chemical analysis was performed. The database called Programa para Pesquisa de Alérgenos de Contato (www.ppac.com.br) was created, in which safe products for patients allergic to dermatological vehicles are provided.

Abstract: Methylisothiazolinone (MI) is a preservative found in cosmetic and industrial products. Contact dermatitis caused by either methylchloroisothiazolinone/methylisothiazolinone (MCI/MI or Kathon CG) or MI has shown increasing frequency. The latter is preferably detected through epicutaneous testing with aqueous MI 2000 ppm, which is not included in the Brazilian standard tray. We describe a series of 23 patients tested using it and our standard tray. A case with negative reaction to MCI/MI and positive to MI is emphasized.