# The history

A 41-year-old man developed at the end of 2023 recurrent acute pulmonary symptoms, with shortness of breath, cough and mild fever. He went to the emergency department several times for that reason, and thoracic imaging (X-ray and CT scan) was carried out each time. They showed bilateral micronodular infiltrate with pseudonodular condensations, associated with a diffuse ground-glass infiltrate. He was systematically treated with antibiotics despite negative microbiological investigations. Symptoms gradually improved with that strategy.

He started developing hemoptyses a few months after which led to hospitalization in an intensive care unit. Microbiological and immune investigations were negatives and both patient and CT scan improved under broad spectrum antibiotics.

He relapsed a month later and was hospitalized in internal medicine department. Physical examination, including breath sounds, was normal despite the patient required 2L/min oxygen therapy. Blood samples showed iron-deficiency anaemia (hemoglobin: 5.4g/dL) with mild elevation of serum C-reactive protein (23mg/L). Fibroscopy with bronchoalveolar lavage was in favour of intra-alveolar haemorrhage (Gold score>100). Respiratory functional exploration was normal with increased KCo. The patient was tested negative for viruses and blood and bronchoalveolar lavage cultures remained both sterile for standard, fungal and mycobacterial cultures. Auto-immunes investigations were again negatives (anti-nuclear antibodies, anti-neutrophil cytoplasmic antibodies, anti-citrullinated peptides antibodies, cryoglobulinemia, and rheumatoid factor). A new CT scan was performed (Fig. 1
                     ).

# The diagnosis

A cocaine-induced diffuse alveolar haemorrhage.

# The comments

The cocaine exposure was documented through urine sample. The patient denied any use but recognized crack smoke exposures through friends. Urine analysis is useful to screen drugs consumption but should be perform rapidly in inpatients. The test might remain positive up to five days in chronic use [1]. Cocaine related intra-alveolar haemorrhage result of vasoconstriction of the pulmonary circulation or of a direct toxic effect, by injuring the alveolar epithelium (through inhalation of toxic substances) [2]. Cocaine may also cause acute pulmonary edema, which is a cause of IAH. There is no specific biological abnormality but anemia, leucocytosis, or eosinophilia are frequent.

In our case, corticosteroids at 0.5mg/kg led to quick improvement. There is no consensual management but patients frequently received immunosuppressive therapy, as it often mimics vasculitis [3]. Cocaine cessation is frequently sufficient in mild case. Cocaine free-base inhalation can lead to a “crack-lung” with can cause severe acute respiratory failure and necessitate intensive care [4]. Long-term complications are lung fibrosis and pulmonary hypertension [5].

Intra-alveolar haemorrhage is a rare but life-threatening disorder, which could be misdiagnosed with community infections. It mainly results from various infection (e.g., tuberculosis, aspergillus) and autoimmune disorders (e.g., ANCA-associated vasculitis, systemic lupus), but investigations should not neglect drugs toxicity (e.g., cocaine, cannabis, amphetamines) [6].

# Human and animal rights

The authors declare that the work described has not involved experimentation on humans or animals.

# Informed consent and patient details

The authors declare that this report does not contain any personal information that could lead to the identification of the patient(s) and/or volunteers.

# Funding

This work did not receive any grant from funding agencies in the public, commercial, or not-for-profit sectors.

# Disclosure of interest

The authors declare that they have no competing interest.

# Authors’ contributions

All authors attest that they meet the current International Committee of Medical Journal Editors (ICMJE) criteria for Authorship..

All authors made a substantial contribution to all of the following:
                        
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                           conceptualization, data curation and formal analysis;
                        
                        
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                           drafting, reviewing and editing of the article;
                        
                        
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                           final approval and validation of the version to be published.