Scleromyxoedema or Arndt-Gottron syndrome is a rare condition of unknown etiology, characterized by the presence of dermal mucin deposits associated with infiltrated sclerotic skin areas. We hereby present the case of a patient 57 years of age, who developed in about six months an infiltrated edema of the skin affecting 65% of the body surface, later associated with progressive limitation of movement of the thorax and severe dyspnea. Dermatologic examination revealed the presence on the thorax and the proximal limbs of sclerotic and infiltrated plaques and placards, with smooth surface, retarding the formation of folds. Erythematous papules arranged linearly and in plaques, on the back of the patient, led to the presumptive diagnosis. Histological examination confirmed the clinical diagnosis. The treatment of the disease is difficult. The literature offers many alternatives. Our patient received corticosteroids, retinoids and PUVA therapy, but has not responded to treatment. Hydroxychloroquine was our only therapeutic option available. Hydroxychloroquine dosage used was the proposed scheme by Terheyden et al., 2003, in an article published in J Dtsch Dermatol Ges. Efficacy was assessed by the clinical aspect, ultrasound imaging of skin and the values of vital capacity and VEMS. After 8 months of treatment whose effectiveness is obvious, the evolution is favorable. We shall continue the treatment and return to the case.