João Borges da Costa

Sweet's syndrome: a retrospective study of 42 admitted patients in a Portuguese hospital

Background  Sweets syndrome is the most common neutrophilic dermatosis, but its pathophysiology is still largely unknown and different subgroups can be defined.

Allergic contact dermatitis to dimethyl fumarate in footwear

Sample 1: insole from black boot 120 Sample 2: tissue lining leather of black boot 640 Sample 3: insole from red boot 11 Sample 4: tissue lining leather of red boot 1.3 or leather sofas and armchairs manufactured in China. This substance has a wide-spectrum biocide activity and it is contained in paper bags, and progressively it can evaporate and contaminate the leather, textiles, food, cosmetic, etc. It is also used to preserve leather of shoes ‘made in China’, and it can cause an acute bullous dermatitis of the feet, as reported here.

Erythema multiforme on exposed and non‐exposed skin following polymorphic light eruption: a case report

We report a 35‐year‐old caucasian female with a history of polymorphic light eruption (PLE) who, after the outbreak of pruritic papules following the first sun exposure of the year, developed target lesions in two different bouts, the first on sun‐exposed skin and the second on sun‐protected sites. A diagnosis of erythema multiforme (EM) developing as a result of PLE was made. As far as we were able to search in the literature, EM occurring in two bouts has not been described previously. We discuss the differential diagnosis.

FENÓMENO PROZONA EM SÍFILIS SECUNDÁRIA. A IMPORTÂNCIA DA COMUNICAÇÃO ENTRE O CLÍNICO E O LABORATÓRIO

The prozone phenomenon is defined as a falsely negative test due to very high titters of antibody, as high titters of antigen or antibody may prevent the formation of antigen-antibody complexes in laboratory tests of many diseases, like syphilis or brucellosis. We describe the case of a 27 year old caucasian male admitted in the emergency room with enlarged palpable lymph nodes and a skin eruption either suggestive of secondary syphilis or primary skin lymphoma. Since initial RPR screen was negative, he was admitted in ward with the latest hypothesis. Skin biopsies were suggestive of syphilis. The laboratory was then contacted to repeat the test under dillutional protocol, which enabled the test to be positive (VDRL 1/256 and TPHA positive). This case illustrates the importance of close contact with the laboratory in order to avoid false negative results, like those given in presence of prozone phenomenon.KEYWORDS – Syphilis, Cutaneous; Syphilis Serodiagnosis; False Negative Reactions.