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International Journal of Clinical & Medical Images


Clinical-Medical Image - International Journal of Clinical & Medical Images (2023) Volume 10, Issue 4

Hypersensitivity Pneumonitis: The Head Cheese Sign

Hypersensitivity Pneumonitis: The Head Cheese Sign

Author(s): Merbouh Sahar*, Kaoutar Imrani, Salma Elhouss, Nabil Moatassimbillah and Ittimade Nassar

Department of Radiology, CHU IBN SINA University Hospital, Mohammed V University, Rabat, Morocco

*Corresponding Author:
Merbouh Sahar
Department of Radiology
CHU IBN SINA University Hospital
Mohammed V University, Rabat, Morocco
Tel: +212 676579947

Received: 21 March 2023, Manuscript No. ijcmi-23-92900; Editor assigned: 22 March 2023, Pre QC No. P-92900; Reviewed: 03 April 2023, QC No. Q-92900; Revised: 08 April 2023, Manuscript No. R-92900; Published: 15 April 2023, DOI:10.4172/2376-0249.1000889

Citation: Sahar M, Imrani K, Elhouss S, Moatassimbillah N and Nassar I. (2023) Hypersensitivity Pneumonitis: The Head Cheese Sign. Int J Clin Med Imaging 10:889.

Copyright: © 2023 Sahar M, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Clinical-Medical Image


Hypersensitivity pneumonitis (HSP) is a form of interstitial lung disease that requires early diagnosis and treatment, as it can lead to progressive pulmonary fibrosis. However, the antigens involved are very diverse and new causes of HSP are frequently identified. Although relatively rare. HSP seems to be under-diagnosed because of its very heterogeneous presentation in its non-fibrosing or fibrosing forms. antigenic avoidance is the rule when possible. Systemic corticosteroid therapy is the first line medical treatment in case of severe hypoxemic form in order to prevent the appearance of fibrosing lesions.

Hypersensitivity pneumonitis (HP) is a diffuse interstitial lung disease (ILD) caused by an immune response secondary to the inhalation of organic or inorganic antigens in the environment in predisposed individuals [1]. It’s a relatively rare pathology that can affect all age groups with no clear gender predominance. All HP may present with aspecific respiratory symptoms such as dyspnea or cough. In some cases, these clinical manifestations accompanied by an influenza-like syndrome, chest pain or weight loss. At the auscultatory level, the presence of high-pitched whistling in the middle of inspiration (“squeaks”) is classic but not specific to HP [2]. The former classification of PHS, which distinguished three clinical entities (acute, subacute and chronic) has recently been abandoned in favor of a classification based on the presence or absence of radiological and/or histopathological fibrosing lesions. Thus, we currently classify non-fibrosing and fibrosing PHS [3]. The diagnosis of PHS is complex due to the heterogeneity of the clinical, radiological and histological presentations of the disease. The exploration of PHS uses high resolution CT (HR-CT) in millimeter slices without injection, performed in deep inspiration, and in prolonged expiration, In non-fibrosing forms, diffuse ground glass opacities and centro-lobular nodules are mainly found, In fibrosing forms, there is a variable association of linear and reticular irregular opacities, ground glass and septal thickening [4] cysts may be associated with the parenchymal lesions, also amphysematous forms have been described. The presence of mosaic attenuation, aerial trapping, ground glass and centrilobular nodules are strong features in centrilobular nodules are strong elements in favour of in favor of the diagnosis of PHS according to an expert consensus [5] Mosaic attenuation is a local combination of areas of two distinct densities corresponding to alternating ground glass and of ground glass and healthy lung or healthy lung and hypodense areas due to air trapping hypodense areas due to air trapping or lowered vascularity, The local association of areas of normal density, increased density and lighter areas produces the “head cheese” sign. The diagnostic criteria for the disease are predominantly based on antigen exposure identification ,clinical and chest HRCT scan pattern, and bronchoscopic/histopathological findings [1].

The first step in treatment is to identify and eliminate the antigen responsible for the disease, but this is not always feasible because it is not always found. However, systemic corticosteroid therapy is considered the first-line medical treatment for severe hypoxemic forms [6].


Hypersensitivity pneumonitis; Imaging; Head cheese sign

Conflict of Interest

The authors are contributed equally and declare no competing interest.


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Citations : 293

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