Can exposure to sulfur mustard, organophosphate (OP) chlorides, combustion products, fuel vapors, ionizing radiation, and non-ionizing radiation cause Pulmonary Fibrosis (PFB)?

From the Guidelines

Exposure to sulfur mustard, organochlorines, combustion products, fuel vapors, ionizing radiation, and exciting radiation is not known to directly cause pseudofolliculitis barbae (PFB). PFB is primarily caused by ingrown hairs that result from shaving, particularly in individuals with curly hair. When a hair is cut at an angle, it can curl back and penetrate the skin, causing inflammation, bumps, and sometimes infection. This condition is most common in men with curly hair, particularly those of African descent, and typically affects the beard area.

Key Points to Consider

• Environmental exposures like those mentioned might potentially worsen skin irritation or inflammation if PFB is already present, but they are not recognized as primary causes of the condition 1.
• The most effective treatments for PFB include proper shaving techniques (using sharp razors, shaving with the grain, using shaving cream), allowing facial hair to grow slightly longer before shaving, or considering alternatives like electric razors or depilatory creams.
• In severe cases, topical treatments containing benzoyl peroxide, antibiotics, or retinoids may be prescribed by a dermatologist.

Relevant Evidence

Studies have shown that various environmental exposures can increase the risk of developing pulmonary fibrosis, but there is no direct link to PFB 1.

Treatment and Prevention

The focus should be on preventing ingrown hairs and reducing skin irritation, rather than addressing potential environmental exposures.

• Proper shaving techniques and alternative hair removal methods can help prevent PFB.
• Topical treatments and medications may be necessary to manage symptoms and prevent infection in severe cases.

From the Research

Exposure to Harmful Substances and PFB

• Exposure to sulfur mustard can cause pulmonary fibrosis, bronchiolitis obliterans, or lung cancer, as seen in victims of World War I and the Iran-Iraq war 2.
• Sulfur mustard can trigger various molecular and cellular pathways that are linked to reactive oxygen species (ROS) generation, oxidative stress, and inflammation, leading to cell death and tissue injury 3.
• Ionizing radiation can also cause pulmonary fibrosis, a common severe long-time complication of radiation therapy for tumors of the thorax 4.
• There is no direct evidence in the provided studies to suggest that organ chlorides, combustion products, fuel vapors, or exciting radiation can cause PFB.
• However, the study on overlapping science in radiation and sulfur mustard exposures suggests that there are striking similarities between injuries caused by radiation and sulfur mustard exposures, including chronic inflammation, oxidative stress, and vascular dysfunction, which can culminate in fibrosis in both skin and lung organ systems 5.

Mechanisms of Injury

• The development of lung fibrosis is a dynamic and complex process, involving the release of reactive oxygen species, activation of Toll-like receptors, recruitment of inflammatory cells, excessive production of nitric oxide, and production of collagen by activated myofibroblasts 4.
• Sulfur mustard can cause oxidative stress induced by reactive oxygen species (ROS), which is likely a significant mechanism by which SM leads to cell death and tissue injury 3.
• Ionizing radiation can also cause oxidative stress and inflammation, leading to fibrosis in the lung 4.

Medical Countermeasures

• Current therapeutic options for radiation-induced pulmonary fibrosis include only supportive management strategies, such as anti-inflammatory treatment using steroids, but their efficacy is far from being satisfactory 4.
• New therapeutic approaches are being developed for idiopathic pulmonary fibrosis, including antifibrotic drugs and nonpharmacological treatments in palliative care, pulmonary rehabilitation, lung transplantation, management of comorbidities, and acute exacerbations 6.
• The development of medical countermeasures for sulfur mustard and radiation exposures is an active area of research, with a focus on novel therapeutic targets and paths to licensure for products to address radiation or SM injuries 5.