Clinical presentation of diffuse parenchymal lung disease

1Classification and example of diffuse parenchymal lung diseases
2Clinical presentation diffuse parenchymal lung diseases
3Management of diffuse parenchymal lung diseases

Clinical presentation of diffuse parenchymal lung disease:

-Cough: usually presented with dry, persistent and distressing cough.
-Breathlessness: usually slowly progressive; insidious onset in nature and sometime acute in some cases, but rare .

Now discuss more about diffuse parenchymal lung disease:

Classification and example of diffuse parenchymal lung diseases:

1) DPLD of known cause: It is mostly Associated with drugs or connective tissue disease, which severely effect the lung parenchyma.

2)Idiopathic interstitial pneumonia(Idiopathic means unknown, reason behind this is still unknown)
-Idiopathic pulmonary fibrosis is the most common type.
-Other than idiopathic pulmonary fibrosis:
-Desquamative interstitial pneumonia
-Acute interstitial pneumonia
-Non-specific interstitial pneumonia
-Cryptogenic organizing pneumonia
-Lymphocytic interstitial pneumonia

3) Granulomatous DPLD:
-Sarcoidosis(due to silica dust which causes permanent irreversible damage to lung)

4) Others:
-Lymphangioleiomyomatosis
-Histiocytosis X

Physical signs:
-Crackles: typically it involve bilaterally and basal part of lung.
-Clubbing: Most common feature in idiopathic pulmonary fibrosis but also may seen in other types, e.g. asbestosis.
-Central cyanosis present and signs of right heart failure in advanced disease.

Radiology:
-Chest X-ray: typically small lung volumes with reticulonodular shadowing but may be normal in early or limited disease.
-High-resolution computed tomegraphy: combinations of ground glass changes, reticulonodular shadowing, honeycomb cysts and traction bronchiectasis, depending on stage of disease.
-Pulmonary function; Typically restrictive ventilatory defect with reduced lung volumes and impaired gas transfer, exercise tests assess exercise tolerance and exercise-related fall in Sao2

One of the most common causes of diffuse parenchymal lung diseases is Sarcoidosis. So with out discussing this ourartical will be incomplete.So we must learn about Sarcodosis:

Sarcoidosis is a multisystem granulomatous disorder of unknown aetiology that is characterised by to presence of non-caseating granulomas.

Aetiology:
-The aetiology remains uncertain.Links with atypical mycobacteria and viruses remain elusive.
-There is some evidence of familial clustering and genetic factors are undoubtedly important,
-Sarcoidosis appears less commonly in smokers.

Clinical features / presentation:
-Asymptomatic – abnormal routine chest X-ray (30%) or abnormal liver function tests.
-Respiratory and constitutional symptoms (20-30%).
-Erythema nodosum and arthralgia (20-30%).
-Ocular symptoms (5-10%).
-Skin sarcoid (including lupus pernio) (5%).
-Superficial lymphadenopathy (5%).
-Other (1%), e.g. hypercalcaemia, diabetes insipidus, cranial nerve palsies, cardiac arrhythmias nephrocalcinosis.

Investigations:
-Complete blood count: Lymphopenia is characteristic.
-Chest radiography: Used to stage sarcoid.
-Liver function tests: May be mildly deranged.
-Serum calcium: May be elevated.
-Serum angiotensin-converting enzyme (ACE): May provide a non-specific marker of disease activity and can assist in monitoring the clinical course.
-Pulmonary function tests: In patients with pulmonary infiltrates pulmonary function may show restrictive defect accompanied by -impaired gas exchange.
-Exercise tests: May reveal oxygen desaturation.
-Bronchoscopy: May demonstrate a ‘cobblestone’ appearance of the mucosa.
-Bronchial and transbronchial biopsy: Usually show non-caseating granulomas.
-The bronchoalveolar lavage fluid: Typically contains an increased CD4 : CD8 T-cell ratio
-High resolution CT scan of chest.

Treatment:

1)Patients who present with acute illness and erythema nodosum should receive NSAIDs and on occasion a short course of corticosteroids.
2) The majority of patients enjoy spontaneous remission and, if there is no evidence of organ damage, it is appropriate to withhold therapy for 4-6 months.
3)Systemic corticosteroids (prednisolone 20-40 mg/day) are also indicated in the presence of hypercalcaemia, pulmonary impairment, renal impairment and uveitis.
4)Topical steroids may be useful in mild uveitis.
5)In patients with severe disease both methotrexate and azathioprine have been used successfully.
6)Chloroquine, hydroxychloroquine and low-dose thalidomide may be useful in cutaneous sarcoidosis with limited pulmonary involvenient.
7)Selected patients may be referred for consideration of single lung transplantation.

FAQ

30 years old lady presented with fever, arhtralgia, painful, palpable, dusky blue-red nodules over the shin of the tibia.
A) What could be the possible diagnosis?
Answer: Possible diagnosis: Sarcoidosis.

B)What is your Differential diagnoses
Answer:
-SLE.
-Tuberculosis.
-Vasculitis.
-Streptococcal infection.

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