No abstract

A 53-year-old male presented with lichenified and excoriated plaques mainly on the hands, forearms and face that had been present since the previous year ( Figure 1). Past medical history was denied. The patient works as a furniture refinisher, using "peroba-rosa" wood (Aspidosperma polyneuron), and denied other possible allergens. A skin biopsy showed spongiotic dermatitis. Patch testing with the Brazilian Contact Dermatitis Group Standard Series 1 was performed, and showed positive reactions to Myroxylon pereirae 10% (balsam of Peru) on day (D) 2 and D4. The patient also had a positive reaction to dust of "peroba-rosa" applied as wood dust wetted with distilled water in an 8-mm aluminium chamber. 136CABEZAS ARTEAGA ET AL. DISCUSSIONThe diagnosis of allergic contact dermatitis is based on a combination of the clinical presentation, a meticulous history, and the results of patch testing. In our patient, the confirmed contact allergen was the wood of A. polyneuron, an exotic hardwood used in construction and furniture, 2 related to the patient's job. A. polyneuron Mueller Argoviensis (Apocynaceae) is a native tree of Brazil, and is typical of the Atlantic forest. 2 The wood of this species has high commercial value. In the literature, there is a series of reports of cases of contact allergy to Aspidosperma sp., found in the wood of an "orange stick" used for manicuring, and in the keyboard of an organ. Jemec and Hausen tested the strong sensitizing potential of this Brazilian wood in guinea-pigs. 3 Our patient also had a positive patch test reaction to M. pereirae. Possible cross-sensitization between trees could be explained by the composition of woods and barks. Aspidosperma sp. contains alkaloids, coumarins, quinones, steroids, triterpenoids, and essential oils. 4 M. pereirae consists of an aromatic liquid derived from the tree bark of Myroxylon balsamum that contains cinnamic aldehyde, cinnamic alcohol, eugenol, isoeugenol, vanillin, benzoic acid, and farnesol. Roesyanto et al reported a rate of 27.2% of combined sensitization to wood tars, fragrance mix and M. pereirae in a population of 1833 patients with proven allergic contact dermatitis. 5 The description of which essential oils are found in hardwoods could give an understanding of the allergen that causes the cross-sensitization. Quinone has already been described as a common allergen among exotic woods. 6,7Continuous exposure to an allergen may produce chronic symptoms. It is important to emphasize the utility of the chemical knowledge of plants. Also, a positive patch test reaction to balsam of Peru may be an important clue regarding wood allergy, although identification of the cross-reacting agent was not possible. Finally, patch testing with suspected woods should be performed in woodworkers, to enable subsequent avoidance of the allergens. ACKNOWLEDGEMENTSWe thank the biologist Mr Ricardo Spina, who assisted in the investigation.

Background Porphyria cutanea tarda (PCT) is the most common porphyria worldwide.The known acquired precipitating factors that induce PCT include alcoholism, hepatitis C virus infection, human immunodeficiency virus infection, and estrogen intake. Hereditary hemochromatosis is considered an inherited risk factor. The aim of this study was to describe and analyze precipitating factors and family history, with emphasis on PCT management. Methods A retrospective study of 87 patients with PCT was conducted between January 2002 and December 2017.Results A male predominance of 1.8 : 1 was found. The median age at diagnosis was 49 years (range 18-71). Family history of PCT was observed in 19.5% of patients. Two or more acquired precipitating factors were present in 42.5%. Patients were treated with antimalarial monotherapy (72.4%), antimalarial combined with phlebotomy (22.9%), and only with phlebotomy (4.6%). Acquired precipitating factors and inherited factors were not associated with treatment group. There was a difference in 24 h-UP normalization rate between treatment groups; combined therapy takes longer than antimalarial monotherapy, 38 months versus 15 months, respectively (CI 95%, 6.5-63.5 vs. 12.9-17) (log-rank test, P = 0.004).Conclusion Precipitating factors did not seem to be associated with treatment choice; however, all acquired and inherited precipitating factors should be investigated, and the choice between phlebotomy and/or antimalarials should be individualized. All dermatologists treating PCT patients should observe transferrin saturation and ferritin levels to search for underlying hereditary hemochromatosis. * P = 0.021 according to a t-test.

No abstract