Occupational toxic epidermal necrolysis associated with dalbergia cochinchinensis: a retrospective comparative study of eight cases in China.

BACKGROUND: Occupational toxic epidermal necrolysis (TEN) related to Dalbergia cochinchinensis has seldom been reported in the past. Its clinical characteristic needs to be investigated. This study reports eight cases of such disease in China. METHODS: Eight patients with occupational TEN admitted from 2003 to 2012 were retrospectively analyzed and compared with 15 patients admitted with TEN caused by drugs as controls. Patients all received combination therapy of corticosteroid and intravenous immunoglobulin. The times for bullous ceasing, tapering of corticosteroid, and total hospitalization were compared between the two groups of patients. SCORTEN, a severity-of-illness scoring system for TEN prognosis, was applied to evaluate clinical outcome. RESULTS: The three time measurements in occupational TEN were longer than those in control, and the differences were statistically significant (P = 0.0023, 0.026, 0.0017), which means the total dose of corticosteroid needed in occupational TEN was higher than that in the control. There were no deaths in the two groups, although expected deaths were 0.612 and 0.836, respectively. DISCUSSION: Occupational TEN has a longer progression than TEN caused by drugs, and there is more difficulty in its treatment. Clinicians should pay attention to this disease. However, its mechanism and target therapy remain unclear.

Contact allergy to a cocobolo bracelet.

Tropical woods are highly valued because of their strength, hardness, and resistance to moisture. These characteristics make them easy to work with and extremely durable, and that is why they have been used in the manufacture of wooden jewelry, musical instruments, furniture, and handles of many different objects. We present a case of a 44-year-old man who developed pruritus, erythema, and blistering around his right wrist, corresponding exactly to the area where he had worn a wooden bracelet. Thin-layer chromatography performed with the extract of the shavings revealed (R)-4-methoxydalbergione and obtusaquinone (the main components of cocobolo wood) and (S)-4'-hydroxy-4-methoxydalbergione (in lower amounts). Patch-testing with sawdust from the bracelet resulted in a very strong reaction. Patch tests with the pure constituents yielded +++ reactions to the main sensitizers of cocobolo, including obtusaquinone, but also to sensitizers present in other rosewoods. This last fact can be explained by cross-reactivity between different dalbergiones. Contact dermatitis from tropical woods is more frequent than thought, owing to their high sensitizing properties. An exhaustive search can identify the allergen responsible in many cases.

Generalized eczematous contact dermatitis from cocobolo wood.

Occupational contact with cocobolo wood (Papilionaceae, Dalbergia retusa) has been reported to rarely cause delayed hypersensitivity reactions. We report the case of a 53-year-old furniture and cabinetmaker who exhibited a generalized reaction mimicking erythroderma after exposure to sawdust from the wood. Patch testing to plants and woods standard (Chemotechnique, Dormer Laboratories, Ontario, Canada) was negative, and the specific allergen in cocobolo, obtusaquinone, was not available to us. The patient was tested instead to shavings of various woods as well as to sawdust of the suspected wood in petrolatum. He exhibited an exuberant response (+++) to both shavings and sawdust of cocobolo. After successful patch testing with shavings and sawdust in the absence of the purified chemical allergen, avoidance of the timber resulted in the resolution of his symptoms.