Atypical and unusual locations of psoriasis are very frequent. However, localized linear psoriasis is rare, with few cases described in the literature. It is characterized by a linear distribution of psoriasis lesions along Blaschko lines. We report the case of a three years old child, who presented unilateral erythematous scaly plaques arranged along Blaschko lines in the left hemithorax, with no associated symptoms and no lesions in other parts of the body. The differentiation of linear psoriasis from other linear dermatoses is not easy. The combination of a thorough history, a careful examination of the skin and histopathology are essential to ensure the correct diagnosis and appropriate treatment.

Chronic cutaneous lupus erythematosus in a linear configuration is rare, particularly in children, demonstrating similar incidence in both genders, no photo-sensitivity and lower probability of progression to systemic disease. We describe the case of a 9-year-old girl who presented erythematous papules with central atrophy on the upper and lower right limbs, asymptomatic and following the lines of Blaschko, since age four. Histological examination showed atrophy of the epidermis with aggression from epidermal-dermal interface and periadnexal and perivascular lymphocytic inflammatory infiltrate. Laboratory tests showed ANA in a titer of 1:320, in a dense and fine speckled pattern. Due to the rarity of presentation and location of the disease, this case is reported here.

This paper describes the association of two unusual side effects of treatment with isotretinoin for severe acne: paronychia and excess granulation tissue in the nails furrows. We report a case of male patient aged 19 years, who in the course of the 36th week of treatment with isotretinoin for acne grade III showed erythema, edema, excess granulation tissue and onychocryptosis in various nail beds of hands and feet, with no history of trauma associated. A literature review revealed few reports of these adverse events, and two clinical patterns of exuberant granulation tissue has been described: one in periungual location and other in lesions of previous acne. The rarity and lack of knowledge on the best treatment for granuloma-like reactions make this theme a considerable challenge.