Fibrosis is the formation of whitish, hard tissue as seen in a scar. Pneumonitis is described as inflammation of the lung, usually due to super sensitivity to a particular substance. Drug-induced pneumonitis and fibrosis are the undesirable response or toxic reaction to one or more drugs.

The mechanism of the injury to the lung is unknown. The injury occurs as a result of an allergic reaction, overdose, side effect, or inappropriate physical response.

Drug toxicity manifestations include: asthma, cough, eosinophilic infiltration, (see Diagnostic Code: 6828 Eosinophilic granuloma of the lung), interstitial fibrosis, (see Diagnostic Code: 6825 Diffuse interstitial fibrosis (interstitial pneumonitis, fibrosing alveolitis), pulmonary edema, pleural effusion, systemic lupus erythematosus (SLE), and respiratory failure. Inhalation of crack cocaine may cause a wide variety of serious effects, such as, acute respiratory failure, alveolar hemorrhage, pneumothorax, or eosinophilia.

Diagnostic testing is not easy because there are no specific x-ray findings or routine laboratory examinations. A medical history, and a high degree of suspicion are the critical elements in the diagnosis.

The offending drug is discontinued immediately, and the acute symptoms usually disappear in 24 to 48 hours.

The symptoms of the chronic syndromes caused by the drug may take longer than 48 hours to resolve.

• May be entitled to special monthly compensation where the Veteran has a single service-connected disability rated as 100% with additional service-connected disability or disabilities independently ratable at 60% or more, which are separate and distinct from the 100% service-connected disability and involves different anatomical segments or bodily systems. See  38 CFR 3.350(i)(1) – Special Monthly Compensation (SMC).

• Review 38 CFR 3.809a for eligibility for entitlement to Special Home Adaptation grants under 38 U.S.C. 2101(b).

• Review special provisions regarding the evaluation of specific respiratory conditions under 38 CFR 4.96(a)- Rating co-existing respiratory conditions and 38 CFR 4.96(d)- Special provisions for the application of evaluation criteria for diagnostic codes 6600, 6603, 6604, 6825–6833, and 6840–6845.