Differential Diagnosis for a Patient with Chest Symptoms, Erythema Nodosum, and Hypercalcaemia: Sarcoidosis vs. Other Conditions

When a patient presents with chest symptoms, erythema nodosum, hypercalcaemia, and signs of systemic inflammation, sarcoidosis is a likely diagnosis. To confirm the diagnosis, a transbronchial biopsy is usually performed to demonstrate the presence of non-caseating granulomata. Alternatively, skin lesions or lymph nodes may provide a source of tissue for biopsy. Corticosteroids are the main treatment for sarcoidosis.

Other conditions that may be considered in the differential diagnosis include asthma, bronchial carcinoma, chronic obstructive pulmonary disease (COPD), and primary hyperparathyroidism. However, the presence of erythema nodosum and bilateral hilar lymphadenopathy are more suggestive of sarcoidosis than these other conditions. While hypercalcaemia may be a symptom of primary hyperparathyroidism, the additional symptoms and findings in this patient suggest a more complex diagnosis.

Correct Order of Structures Traversed in Chest Drain Insertion

When inserting a chest drain, it is important to know the correct order of structures that will be traversed. The order is as follows: skin, external intercostal muscle, internal intercostal muscle, innermost intercostal muscle, and parietal pleura.

The external intercostal muscles are encountered first in chest drain insertion before the internal and innermost intercostal muscles, as suggested by their names. The skin is the first structure to be traversed by the tube. The parietal pleura lines the inner surface of the thoracic cavity and is the outer boundary of the pleural cavity. The chest drain tip should enter the pleural cavity which is bound by the parietal and visceral pleura. The parietal pleura is therefore encountered before reaching the visceral pleura. The visceral pleura should not be penetrated in chest drain insertion.

Knowing the correct order of structures to be traversed during chest drain insertion is crucial to ensure the procedure is done safely and effectively.

CT Pulmonary Angiography as the Preferred Diagnostic Tool for Pulmonary Embolism

Computerised tomography (CT) pulmonary angiography is the most suitable diagnostic tool for patients suspected of having a pulmonary embolism. This is particularly true for patients with chronic lung disease, as a ventilation perfusion scan may be difficult to interpret. In this case, the patient almost certainly has a pulmonary embolism, making CT pulmonary angiography the investigation of choice.

It is important to note that while ventilation perfusion scans are useful in diagnosing pulmonary embolisms, they may not be the best option for patients with underlying lung disease. This is because the scan can be challenging to interpret, leading to inaccurate results. CT pulmonary angiography, on the other hand, provides a more accurate and reliable diagnosis, making it the preferred diagnostic tool for patients suspected of having a pulmonary embolism.

Respiratory Disorders: Bronchiolitis Obliterans, ARDS, Pneumocystis Pneumonia, COPD Exacerbation, and Idiopathic Pulmonary Hypertension

Bronchiolitis obliterans (BO) is a respiratory disorder that may occur after bone marrow, heart, or lung transplant. It presents with an obstructive pattern on spirometry, low DLCO, and hypoxia. CT scan shows air trapping, and chest X-ray may show interstitial infiltrates with hyperinflation. BO may also occur in connective tissue diseases, such as rheumatoid arthritis, and idiopathic variety called cryptogenic organising pneumonia (COP). In contrast, acute respiratory distress syndrome (ARDS) patients deteriorate quickly, and pneumocystis pneumonia usually presents with normal clinical findings. Infective exacerbation of chronic obstructive pulmonary disease (COPD) is associated with a productive cough and raised CRP, while idiopathic pulmonary hypertension has a restrictive pattern and inspiratory fine crepitations.

Diagnostic Criteria for Asthma: Key Indicators to Consider

Asthma is a chronic respiratory disease that affects millions of people worldwide. It is characterized by airway inflammation, bronchoconstriction, and increased mucous production, leading to symptoms such as wheezing, coughing, and shortness of breath. Diagnosing asthma can be challenging, as its symptoms can mimic those of other respiratory conditions. However, several key indicators can help healthcare professionals make an accurate diagnosis.

Fraction exhaled nitric oxide (FeNO) 50 parts per billion (ppb): An FeNO level > 40 ppb is indicative of asthma.

Forced expiratory volume in 1 second/forced vital capacity ratio (FEV1/FVC ratio) ≥ 75%: An obstructive FEV1/FVC ratio < 70% would support a diagnosis of asthma in this patient. A 10% or higher improvement in FEV1 following a nebulised bronchodilator: A 12% or higher improvement in FEV1 following a nebulised bronchodilator supports a diagnosis of asthma. A 150 ml or higher improvement in FEV1 following a nebulised bronchodilator: A 200 ml or higher improvement in FEV1 following a nebulised bronchodilator supports a diagnosis of asthma. Greater than 15% variability in peak expiratory flow rate (PEFR) on monitoring: Greater than 20% variability in PEFR on monitoring supports a diagnosis of asthma. In conclusion, healthcare professionals should consider these key indicators when diagnosing asthma. However, it is important to note that asthma is not the only cause of these indicators, and a comprehensive evaluation of the patient’s medical history, physical examination, and other diagnostic tests may be necessary to make an accurate diagnosis.

Needle Thoracocentesis for Tension Pneumothorax

Explanation:
In cases of traumatic chest pain, it is important to keep an open mind regarding other injuries. However, if a patient rapidly deteriorates with signs of shock, hypoxia, reduced chest expansion, and no breath sounds audible on the affected side of the chest, a tension pneumothorax should be suspected. This is an immediately life-threatening condition that requires immediate intervention.

There is no time to wait for confirmation on a chest X-ray or to set up a chest drain. Instead, needle thoracocentesis should be performed on the affected side of the chest. A large-bore cannula is inserted in the second intercostal space, mid-clavicular line, on the affected side. This can provide rapid relief and should be followed up with the insertion of a chest drain.

It is important to note that there is no role for respiratory consultation or nebulisers in this scenario. Rapid intervention is key to preventing cardiac arrest and improving patient outcomes.

Types of Lung Cancer and Cavitating Lesions

Lung cancer can be classified into different subtypes based on their histology and response to treatments. Among these subtypes, squamous cell carcinoma is the most common type that causes cavitating lesions on a chest X-ray. This occurs when the tumour outgrows its blood supply and becomes necrotic, forming a cavity. Squamous cell carcinomas are usually centrally located and can also cause ectopic hormone production, leading to hypercalcaemia.

Other causes of cavitating lesions include pulmonary tuberculosis, bacterial pneumonia, rheumatoid nodules, and septic emboli. Bronchoalveolar cell carcinoma is an uncommon subtype of adenocarcinoma that does not commonly cavitate. Small cell carcinoma and large cell carcinoma also do not commonly cause cavitating lesions.

Adenocarcinoma, on the other hand, is the most common type of lung cancer and is usually caused by smoking. It typically originates in the peripheral lung tissue and can also cavitate, although it is less common than in squamous cell carcinoma. Understanding the different types of lung cancer and their characteristics can aid in diagnosis and treatment.

Methotrexate as a Cause and Treatment for Pulmonary Fibrosis

Pulmonary fibrosis is a condition where the lung tissue becomes scarred and thickened, making it difficult for the lungs to function properly. Methotrexate, a chemotherapy drug, is a known cause of pulmonary fibrosis. However, it is also sometimes used as a treatment for idiopathic pulmonary fibrosis as a steroid sparing agent.

According to medical research, other chemotherapy drugs such as alkylating agents, asparaginase, bleomycin, and procarbazine have also been linked to pulmonary parenchymal or pleural reactions in patients with malignant diseases. In addition, drug-related interstitial pneumonia should be considered in rheumatoid arthritis patients who are taking methotrexate or newer drugs like leflunomide.

Despite its potential risks, methotrexate can be a useful treatment option for some patients with pulmonary fibrosis. However, it is important for healthcare providers to carefully monitor patients for any adverse reactions and adjust treatment plans accordingly.

Managing Occupational Asthma: Redeployment and Avoiding Suboptimal Treatment Options

Based on the evidence from the patient’s peak flow diary, it is likely that they are suffering from occupational asthma. This could be due to a number of agents, such as glutaraldehyde used in hospital sterilisation units. The best course of action would be to redeploy the patient to another role, if possible, and monitor their peak flows at work. Starting medical management for asthma would not be the optimal choice in this case. Other causes of occupational asthma include isocyanates, metals, animal antigens, plant products, acid anhydrides, biological enzymes, and wood dusts. While salbutamol inhaler may provide temporary relief, it is not a long-term solution. Inhaled steroids like beclomethasone or fluticasone/salmeterol may help manage symptoms, but since the cause has been identified, they would not be the most appropriate course of action. A 7-day course of oral prednisolone would only provide temporary relief and is not a realistic long-term treatment option.

The patient is displaying symptoms that are typical of acute sarcoidosis, including erythema nodosum, bilateral hilar lymphadenopathy, and arthralgia. The patient’s ethnic background, being Afro-Caribbean, is also a factor as sarcoidosis is more prevalent in this population. It is important to take a thorough medical history as sarcoidosis can mimic other diseases. Mycoplasma pneumonia presents with flu-like symptoms followed by a dry cough and reticulonodular shadowing on chest X-ray. Pneumocystis jirovecii pneumonia causes breathlessness, fever, and perihilar shadowing on chest X-ray and is associated with severe immunodeficiency. Pulmonary TB causes cough, fever, weight loss, and erythema nodosum, with typical chest X-ray findings including apical shadowing or cavity, or multiple nodules. Pulmonary fibrosis presents with shortness of breath, a non-productive cough, and bilateral inspiratory crepitations on auscultation. However, the X-ray findings in this patient are not consistent with pulmonary fibrosis as reticulonodular shadowing would be expected.