Chronic occupational exposure to lead leads to significant mucocutaneous changes in lead factory workers

Chronic lead toxicity is a worldwide public health problem. Lead possesses deleterious effects on many organ systems. However, little is known regarding its clinical and biophysical effects on the skin.

To investigate mucocutaneous signs and biophysical property changes in skin after chronic lead toxicity.

One hundred and eighty-seven patients who were car battery workers participated in the study. Complete history and physical examination were performed. Blood was collected for laboratory analyses. Thorough skin examination by dermatologists was carried out in 134 subjects. Additionally, 96 patients with blood lead levels (BLL) >70 μg/dL were further evaluated for skin elasticity, sebum content, transepidermal water loss (TEWL), hydration, pH and pigmentation. An equal number of age-, sex- and skin-type-matched subjects were recruited as controls.

The mean BLL of all subjects was 74.15 ± 11.58 μg/dL. The most frequently observed signs were gingival brown pigmentation in 112 (83.6%), gingivitis in 111 (82.8%) and lead line in 66 (49.3%) patients. The lead line was found in subjects with significantly higher BLLs (adjusted mean difference 6.45, 95% CI 2.30-10.60 μg/dL, P = 0.003) and in association with gingivitis (adjusted OR 7.32, 95% CI 2.08-25.74, P = 0.002). Mean BLL of the patients who underwent biophysical assessment was 82.77 ± 9.80 μg/dL. Patients exhibited a statistically significant lower skin hydration observed by corneometer as well as elasticity. The adjusted ORs of having dry skin and lower elasticity were 15.32 (95% CI 4.41-53.24), P < 0.001) and 1.96 (95% CI 1.06-3.60), P = 0.031), respectively. These differences were not significant for sebum content, TEWL, pH and pigmentation.

Importantly, even in normal-appearing skin, level of hydration and elasticity decreased in lead-intoxicated patients. These results suggest that lead might possess harmful effects on the skin at measurable levels.