Abstract Pili torti also known as ‘twisted hairs’ (Latin: pili=hair; torti=twisted) is a rare, congenital or acquired clinical presentation, in which the hair shaft is flattened at irregular intervals and twisted 180º along its axis. It is clinically characterized by fragile, brittle, coarse and lusterless hairs, due to uneven light reflection on the twisted hair surface. Pili torti may be associated with neurological abnormalities and ectodermal dysplasias. There is no specifi c treatment for this condition, but it may improve spontaneously after puberty. We report a case of pili torti in a child who presented fragile, brittle, diffi cult to comb hair. The patient had no comorbidities.

Abstract Darier’s disease is characterized by dense keratotic lesions in the seborrheic areas of the body such as scalp, forehead, nasolabial folds, trunk and inguinal region. It is a rare genodermatosis, an autosomal dominant inherited disease that may be associated with neuropsichiatric disorders. It is caused by ATPA2 gene mutation, presenting cutaneous and dermatologic expressions. Psychiatric symptoms are depression, suicidal attempts, and bipolar affective disorder. We report a case of Darier’s disease in a 48-year-old female patient presenting severe cutaneous and psychiatric manifestations.

Hansen's disease is a chronic infecto-contagious disease caused by Mycobacterium leprae. The bacillus prefers low-temperature areas and the nose is usually the initial site of lesions. Transmission of the bacilli occurs by nasal and oropharyngeal secretions, and through solutions of continuity of the skin and/or mucosae. Nasal manifestations are found in the later stages of the disease.

Trichilemmoma is a benign neoplasm from the outer sheath of the pilosebaceous follicle. Desmoplastic trichilemmoma, a rare variant, is histologically characterized by a central area of desmoplasia that can clinically mimic an invasive carcinoma, requiring histopathological examination to define the diagnosis.

The yellow nail syndrome is a rare disorder characterized by the classic triad of yellow and dystrophic nails, lymphedema and pleural effusion. We report in this paper a case of yellow nail syndrome, presenting the classic triad of the disease, associated with an unusual lymph accumulation in the abdomen region.

Cutis verticis gyrata is characterized by excessive formation of scalp skin. It may be primary (essential and nonessential) or secondary. In the primary essential form it presents only folding skin formation on the scalp, mimicking cerebral gyri, without associated comorbidities. We report a rare case of a 28 year-old male patient with primary essential cutis verticis gyrata.