Publish in this journal
Journal Information
Vol. 48. Issue 1.
Pages 29-31 (January 2012)
Vol. 48. Issue 1.
Pages 29-31 (January 2012)
Case Report
DOI: 10.1016/j.arbr.2011.04.008
Full text access
Hypersensitivity Pneumonitis Related to Medium-Density Fiberboard
Neumonitis por hipersensibilidad en relación a madera de densidad media
Ramón Toribioa, María Jesús Cruza,b,
Corresponding author

Corresponding author.
, Ferran Morella,b, Xavier Muñoza,b,c
a Servicio de Neumología, Hospital Valle de Hebrón, Departamento de Medicina, Universidad Autónoma de Barcelona, Barcelona, Spain
b CIBER de enfermedades respiratorias (CibeRes), Instituto de Salud Carlos III, Madrid, Spain
c Departamento de Biología Celular, Fisiología e Inmunología, Universidad Autónoma de Barcelona, Barcelona, Spain
Article information
Full Text
Download PDF
Figures (2)

Pneumonitis due to hypersensitivity to wood fiber is mainly associated with the fungus that colonizes it. We present the case of a male affected with hypersensitivity pneumonitis in which the agent implicated was medium-density fiberboard, an engineered product whose main component is pine wood fiber. The causal agent was identified by means of a specific bronchial provocation test.

Hypersensitivity pneumonitis
Occupational pathology
Specific bronchial provocation test

La neumonitis por hipersensibilidad en relación a maderas se asocia principalmente a los hongos que las colonizan. Presentamos el caso de un varón afecto de neumonitis por hipersensibilidad en el que el agente implicado fue una madera de densidad media, producto industrial cuyo principal componente es la madera de pino. La identificación del agente causal se realizó por medio de una prueba de provocación bronquial específica.

Palabras clave:
Neumonitis por hipersensibilidad
Patología ocupacional
Prueba de provocación bronquial específica
Full Text

Hypersensitivity pneumonitis (HP) is a disease that is characterized by an abnormal immune reaction to the exposure to different antigens over a prolonged period of time, and its immunopathogenesis is related with delayed hypersensitivity mediated by T-cells.1,2 Although there is an association between this pathology and certain occupations, it is not a disease that entails mandatory reporting and therefore its prevalence and incidence are difficult to estimate.3 One of the occupations involved in the genesis of this disease has been carpentry. In this regard, although some reported cases have demonstrated that the antigens of the wood itself are the causal agent,4,5 usually it is the fungi that colonize the wood that are responsible for the disease.6–9

We present the case of HP in a carpenter in whom the agent involved was medium-density fiberboard (MDF), an industrial product that is a variation of particle board.

Case Report

The patient is a 37-year-old male, with no toxic habits and with no known pathological history. As a professional carpenter since the age of 16, he has been in contact with mainly MDF, and usually has not used protection while working.

The patient complained of dry cough, dyspnea, low-grade fever, chest pain, arthromyalgia and persistent asthenia over the last 7 years. Said symptoms improved while the patient was on vacation.

The physical examination was normal, and the general work-up showed no relevant findings. Lung function studies showed a forced vital capacity (FVC) of 4.94 l (91%), forced expiratory volume in 1s (FEV1) of 3.96 l (93%), FEV1/FVC ratio 80%, residual volume (RV) 80%, total lung capacity (TLC) 91%, carbon monoxide diffusing capacity (DLCOsb) 75% and (DLCOva) 88%. Both the bronchodilator test and the non-specific bronchial provocation test with methacholine were negative. Chest computed tomography (CT) showed a micronodular pattern with patchy areas of ground glass (Fig. 1).

Fig. 1.

Chest computed tomography shows a micronodular pattern with patchy ground glass areas.


The culture of the wood responsible for the patient's symptoms was positive for Candida sp. The immediate skin reaction tests for Candida sp., Penicillium frequentans and Aspergillus fumigatus were negative. The determinations of G immunoglobulin by means of the ELISA technique for Candida sp., P. frequentans and A. fumigatus were also negative. A specific bronchial provocation test (BPT) with a commercial Candida sp. extract, performed following the recommendations proposed by our group,2 was negative. A second BPT with direct exposure of the patient to the wood product in question in a provocation booth for 60min was positive after confirming a decrease in FVC of 15% and in DLCO of 21% with an increase in temperature of 0.6°C, going from 36.5 to 37.1°C and starting 5h after the beginning of the exposure (Fig. 2). None of these changes were observed when the patient was exposed to a placebo the previous day. Twenty-four hours after the exposure, bronchoscopy with bronchoalveolar lavage (BAL) demonstrated a cell count with 80% macrophages, 18% lymphocytes and 2% polymorphonuclear cells.

Fig. 2.

Specific bronchial provocation test (BPT) against medium-density fiberboard (MDF). The test was considered positive with an observed decrease in FVC of 15%, a decrease in DLCO of 21% and an increase in temperature of 0.6°C. DLCO: carbon monoxide diffusing capacity; FVC: forced vital capacity.


After the exposure, the patient remained asymptomatic, and the thoracic CT as well as the different lung function studies normalized.


We report the case of a patient with HP to MDF wood, an industrial product that is a variation of fine-particle board whose main component is pine wood. The clinical symptoms that the patient presented, as well as the radiological findings and a mild reduction in the CO diffusion test, suggested the diagnosis of HP. As the patient clearly related the symptoms with the exposure to MDF, BPT was then carried out in order to both ensure the diagnosis and establish the causal agent. The disappearance of the symptoms and the normalization of the radiology after the exposure confirmed the diagnosis.1,2 The fact that the wood culture was only positive for Candida sp., that the immunological tests were negative for the different fungi tested, and that the provocation test was positive for MDF sawdust and not for Candida sp. extract all suggest that the wood itself is the cause of the patient's illness.

In general, when a patient in contact with wood is diagnosed with HP, the etiological agent is usually a fungus. There are certainly references in this direction, and the most frequently involved fungi are Aspergillus species, Penicillium species, Cryptostroma corticale, Alternaria, Graphium, Aureobasidium pullulans, Mucor sp. and Trichoderma spp.6–10 We have not found any references relating Candida sp. as a causal agent of HP related to wood exposure, although it is known to be related to the use of humidifiers.11–13

There are also cases in which the wood itself has been identified as the causal agent. The types of wood implicated are red cedar, iroko, ramin, oak and mahogany.14 In general, the diagnoses were established by BPT and by determination of specific antibodies against wood extracts. Our group has also been able to demonstrate the involvement of cork wood as a cause of HP. After studying eight patients with suberosis by determining specific IgG antibodies and carrying out skin tests and BPT for cork and different fungi, it was demonstrated that the only causal agent was the cork itself in at least one patient, while its involvement was not clear in another two patients.5

Recently, Malmstrom et al.4 have demonstrated a response of specific IgG antibodies to pine carbohydrates in a patient with HP, suggesting that said compositions could also be involved in the genesis of this entity. Said authors ruled out the fungal etiology although no specific bronchial provocation test was done. In this sense, we cannot exclude that the origin of the HP of the patient that we have presented here may be the exposure to said molecules, keeping in mind that the main component of MDF is pine wood.

In conclusion, after excluding the fungal etiology of this HP, we can affirm that it is caused by the MDF itself. We believe in the relevance of this contribution as these wood products are currently widely used in our society.

Y. Lacasse, M. Selman, U. Costabel, J.C. Dalphin, M. Ando, F. Morell, et al.
Clinical diagnosis of hypersensitivity pneumonitis.
Am J Respir Crit Care Med, 168 (2003), pp. 952-958
F. Morell, A. Roger, L. Reyes, M.J. Cruz, C. Murio, X. Munoz.
Bird fancier's lung: a series of 86 patients.
Medicine (Baltimore), 87 (2008), pp. 110-130
J.C. McDonald, Y. Chen, C. Zekveld, N.M. Cherry.
Incidence by occupation and industry of acute work related respiratory diseases in the UK, 1992–2001.
Occup Environ Med, 62 (2005), pp. 836-842
K. Malmstrom, L. Savolainen, E.O. Terho.
Allergic alveolitis from pine sawdust.
Allergy, 54 (1999), pp. 532-533
F. Morell, A. Roger, M.J. Cruz, X. Munoz.
Suberosis. Clinical study and new etiologic agents in a series of eight patients.
Chest, 124 (2003), pp. 1145-1152
M.S. Dykewicz, P. Laufer, R. Patterson.
Woodman's disease: hypersensitivity pneumonitis from cutting live trees.
J Allergy Clin Immunol, 81 (1988), pp. 455-460
X. Baur, G. Gahnz, Z. Chen.
Extrinsic allergic alveolitis caused by Cabreuva wood dust.
J Allergy Clin Immunol, 106 (2000), pp. 780-781
A. Villar, X. Munoz, M.J. Cruz.
Neumonitis por hipersensibilidad a Mucor sp en un trabajador de la industria del corcho.
Arch Bronconeumol, 45 (2009), pp. 405-407
D.M. Halpin, B.J. Graneek, M. Turner-Warwick, A.J. Newman Taylor.
Extrinsic allergic alveolitis and asthma in a sawmill worker: case report and review of the literature.
Occup Environ Med, 51 (1994), pp. 160-164
F. Morell.
Usefulness of specific skin test in the diagnosis of hypersensitivity pneumonitis.
J Allergy Clin Immunol, 110 (2002), pp. 939
T. Suda, A. Sato, M. Ida, H. Gemma, H. Hayakawa, K. Chida.
Hypersensitivity pneumonitis associated with home ultrasonic humidifiers.
Chest, 107 (1995), pp. 711-717
E. Ordoqui, M. Orta, A. Aranzábal, M.C. Martínez, F. Idoate, M.J. Trujillo, et al.
Alveolitis alérgica extrínseca por exposición a humidificador ultrasónico.
Alergol Inmunol Clin, 15 (2000), pp. 400-404
C. Serrano, A. Torrego, A. Loosli, A. Valero, C. Picado.
Hypersensitivity pneumonitis after exposure to Candida spp..
Arch Bronconeumol, 46 (2010), pp. 275-277
A.D. Howie, G. Boyd, F. Moran.
Pulmonary hypersensitivity to Ramin (Gonystylus bancanus).
Thorax, 31 (1976), pp. 585
Copyright © 2011. SEPAR
Archivos de Bronconeumología (English Edition)

Subscribe to our newsletter

Article options
es en

¿Es usted profesional sanitario apto para prescribir o dispensar medicamentos?

Are you a health professional able to prescribe or dispense drugs?

es en
Política de cookies Cookies policy
Utilizamos cookies propias y de terceros para mejorar nuestros servicios y mostrarle publicidad relacionada con sus preferencias mediante el análisis de sus hábitos de navegación. Si continua navegando, consideramos que acepta su uso. Puede cambiar la configuración u obtener más información aquí. To improve our services and products, we use "cookies" (own or third parties authorized) to show advertising related to client preferences through the analyses of navigation customer behavior. Continuing navigation will be considered as acceptance of this use. You can change the settings or obtain more information by clicking here.