Having in mind the frequent asymptomatic nature of coal worker's pneumoconiosis (CWP) or silicosis, the principal occupational factors in the pathogenesis of Caplan syndrome, patients often present with little or no respiratory symptoms [1] [2]. Mild dyspnea, most notably on exertion, was noted as the principal complaint in recent case reports [1] [2], while a cough and hemoptysis are absent. In fact, the disease is often discovered incidentally, while virtually all patients present with one or more manifestations of rheumatoid arthritis (RA) [2] [3]:

• Polyarthritis, tendinitis, bursitis - Most commonly involving the wrist and hand joints; profound inflammation seen in RA causes polyarthritis accompanied by morning stiffness, usually in a symmetrical fashion.
• Nodules - Firm, nontender nodules that develop most frequently in the forearms, calfs, and the sacrum, are one of the main features of RA, and their subcutaneous appearance may be followed by their development in visceral organs, including the lungs, which is the cardinal feature of Caplan syndrome.
• Constitutional symptoms - Fever, fatigue, malaise and cachexia ensue as a result of extensive inflammatory changes.

Although seen in a very small number of patients, cardiac (ischemic heart disease, cardiomyopathy, pericarditis) and hematologic (anemia, neutropenia, splenomegaly) features may also be encountered in RA patients [3].

• Vietnamese

  Русский (Russian) ಕನ್ನಡ (Kannada) 한국어 (Korean) עברית (Hebrew) Український (Ukrainian) اردو (Urdu) Magyar (Hungarian) मानक हिन्दी (Hindi) Indonesia (Indonesian) Italiano (Italian) தமிழ் (Tamil) Türkçe (Turkish) తెలుగు (Telugu) ภาษาไทย (Thai) Tiếng Việt (Vietnamese [synonyms.com]

• Constitutional Symptom

  Constitutional symptoms - Fever, fatigue, malaise and cachexia ensue as a result of extensive inflammatory changes. [symptoma.com]

• Cough

  Examination of the chest may show diffuse rales that do not disappear on coughing or taking a deep breath. [patient.info]

  Examination should reveal tender, swollen metacarpophalangeal joints and rheumatoid nodules ; auscultation of the chest may reveal diffuse râles that do not disappear on coughing or taking a deep breath. [en.wikipedia.org]

  Clinical findings Swollen joints, rheumatoid nodules, cough and dyspnoea. [medical-dictionary.thefreedictionary.com]

• Dyspnea

  Mild dyspnea, most notably on exertion, was noted as the principal complaint in recent case reports, while a cough and hemoptysis are absent. [symptoma.com]

  Review Topic QID: 100904 4 Malignant pulmonary mesothelioma M1 Select Answer to see Preferred Response PREFERRED RESPONSE 5 (M1.PL.118) A 42-year-old male presents to your office complaining of dyspnea on exertion. [medbullets.com]

  Once the disease progresses, patients can develop dyspnea that is typically progressive. If left untreated, patients can develop signs of right-sided heart failure. [lecturio.com]

  She came to the Bayview ER, complaining of dyspnea on exertion (DOE), a worsening cough from her baseline and saturating about 78 to 80% on room air. A week before the onset of these symptoms, she had a low-grade fever. [hopkinsarthritis.org]

• Rales

  Examination of the chest may show diffuse rales that do not disappear on coughing or taking a deep breath. [patient.info]

• Productive Cough

  She did have a non-productive cough, but it was much of a problem for her. She was certainly saturating less than 90% on room air. Her DLCO was right at 71% predicted, and her white count was 8,000. [hopkinsarthritis.org]

  Patients with simple CWP can be asymptomatic or can present with non-specific symptoms such as a productive cough. Once the disease progresses, patients can develop dyspnea that is typically progressive. [lecturio.com]

• Chronic Cough

  Patients with unexplained weight loss, fever, night sweats and chronic cough might have a superimposed mycobacterial infection and specific treatment for mycobacterial infection should be started. [lecturio.com]

  Case 3 The woman who had a chronic cough and a high-resolution CT that showed some bronchial thickening. She was obstructive. DLCO was also diminished. [hopkinsarthritis.org]

• Morning Stiffness

  stiffness, usually in a symmetrical fashion. [symptoma.com]

  In addition there are the features of rheumatoid arthritis (RA) with painful joints and morning stiffness. Signs There are features of RA, including tender swollen metacarpophalangeal (MCP) joints and rheumatoid nodules. [patient.info]

• Joint Swelling

  Cough Joint swelling and pain Nodules of the skin (rheumatoid nodules) Shortness of breath Wheezing What to do now? If you believe you are suffering from Caplan Syndrome or have been diagnosed with it you may able to claim compensation. [lpsolicitors.co.uk]

  Symptoms Cough Joint swelling and pain Nodules of the skin (rheumatoid nodules) Shortness of breath Wheezing Signs and tests Your health care provider will take a detailed medical history that will include questions about your jobs (past and present) [coordinatedhealth.com]

  Joint Swelling The arthritis in Caplan’s syndrome causes swelling in the joints. The swollen skin is tender to touch and sometimes may reflect redness and warmth. The swelling may increase with exertion on the joints and pain emanating therefrom. [findarthritistreatment.com]

  Joint swelling and pain. Treatment of Caplan’s Syndrome or Coal Workers Pneumoconiosis No particular cure is available for the treatment of Caplan’s syndrome. [epainassist.com]

  Joint swelling can be a symptom of a chronic condition, such as arthritis, or an injury that requires medical attention, such as a dislocation. What causes joint swelling? One of the most frequent causes of joint swelling is arthritis. [healthline.com]

• Short Arm

  Yet in the last two decades as many as 124 different HLA antigens determined by at least 7 very closely linked genes located on the short arm of chromosome 6 have been identified and subsequently agreed upon by an international nomenclature committee. [books.google.com]

• Joint Tenderness

  […] hands Soft tissue swelling Periarticular osteopenia (particularly characteristic) Loss of joint space – occurs in OA as well Periarticular erosions Bony deformity Subluxation Assessment of severity in rheumatoid arthritis DAS28 scoring Number of swollen joints [oxfordmedicaleducation.com]

Because Caplan syndrome is strongly associated with occupational exposure to coal dust or silica, a detailed patient history with an emphasis on previous occupations may be one of the most important steps during workup. Similarly, assessment of signs and symptoms suggestive of RA (if the diagnosis is not already known) can only be made after a meticulous history taking, but the role of a thorough physical examination is equally important. The diagnosis of Caplan syndrome, however, relies on findings obtained from imaging studies - radiography and computed tomography (CT) of the thorax [4] [5]. Well-defined lung nodules that range from 0.5-5 cm, predominantly located in the periphery, are typical radiographic lesions seen in these patients [1] [4]. Coalescence of nodules and formation of a large confluent nodule, cavitation or calcification may also be observed [4]. On the other hand, confirmation of RA is necessary by performing appropriate laboratory tests, in addition to clinical criteria. Evaluation of C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) antibodies are mandatory if clinical suspicion toward RA exists. The combination of radiographic findings, occupational risk factors, and laboratory results should be sufficient to make the diagnosis of Caplan syndrome.

• Kerley A Lines

  Fleischer （1874-1965）German ophthalmologist Kearns-Sayre カーンズ・セイヤー Kearns-Sayre syndrome カーンズ・セイヤー症候群 Keith-Flack キース・フラック Keith-Flack node キース・フラック小結節 Keith-Wagener キース・ワグナー Keith-Wagener classification キース・ワグナー分類 Kent ケント Kent bundle ケント束 Kerley カーリー Kerley [jams.med.or.jp]

• Pulmonary Infiltrate

  Rheumatoid arthritis extra-articular manifestations : • arm paresthesias and hyperreflexia C1-C2 subluxation (increased risk with intubation) • cough, fever, pulmonary infiltrates bronchiolitis obliterans organizing pneumonia • foot drop or wrist drop [mnemocine.wordpress.com]

• Elevated Sedimentation Rate

  Patients very commonly have an elevated sedimentation rate. Pulmonary function tests show a restrictive pattern with a reduced DLCO and BAO and usually show a lymphocytic infiltrate. [hopkinsarthritis.org]

• Restrictive Pulmonary Function

  The second-most helpful positive predictive finding was the restrictive pulmonary function test finding. This is what we’d expect to find just on chest X-ray with parenchyma involvement and verticular nodule finding and chest CT with the same. [hopkinsarthritis.org]

1. De Capitani EM, Schweller M, Silva CM, Metze K, Cerqueira EM, Bértolo MB. Rheumatoid pneumoconiosis (Caplan's syndrome) with a classical presentation. J Bras Pneumol. 2009;35(9):942-946.
2. Rozenberg D, Shapera S. What to do with all of these lung nodules? Can Respir J. 2014;21(3):e52-e54.
3. Longo DL, Fauci AS, Kasper DL, Hauser SL, Jameson J, Loscalzo J. eds. Harrison's Principles of Internal Medicine, 18e. New York, NY: McGraw-Hill; 2012
4. Schreiber J, Koschel D, Kekow J, Waldburg N, Goette A, Merget R. Rheumatoid pneumoconiosis (Caplan's syndrome). Eur J Intern Med. 2010;21(3):168-72.
5. Arakawa H, Honma K, Shida H, Saito Y, Morikubo H. Computed tomography findings of Caplan syndrome. J Comput Assist Tomogr. 2003;27(5):758-760..