In children, should we really be scared about staining teeth with doxycycline treatment?

Studies in the 1960s demonstrated dental staining with the use of tetracycline in children 2–8 years of age.¹ For this reason, it was recommended that it not be used in younger children. These findings were extrapolated to include doxycycline—which binds with less affinity to calcium than tetracycline. Does the modern literature support this?

A blinded, randomized, controlled study by Volovitz et al evaluated 61 children ages 8–16 years for dental staining of permanent teeth after receiving doxycycline for asthma exacerbations.² Of note, permanent teeth begin to calcify after birth, incisors are usually completely calcified by 5 years of age, and the remainder of permanent teeth—with the exception of molars—completely calcify by about 8 years. The study assessed 31 children who had received doxycycline treatment prior to age 8. Of those, 21 received doxycycline prior to age 4 years. There were 30 controls in this study. The median number of doxycycline treatments was two courses, and the time elapsed from the first course ranged from 2–12 years until the teeth were assessed for permanent staining. While the sample numbers are small, no children in either group demonstrated any permanent tooth staining.

Additionally, a retrospective cohort study by Todd et al evaluated 58 Native American children ages 8–16 years for permanent dental staining following doxycycline exposure for the treatment of Rocky Mountain spotted fever (RMSF). The children who took doxycycline were compared to 213 children without exposure in a blinded fashion.³ The average age at the time of exposure to doxycycline was 4.5 years (range 0.2–7.9 years), and the average number of doxycycline courses was 1.8 courses. The average doxycycline course was 7.3 days (range 1–10 days). Like the previous study, no children demonstrated tetracycline-like permanent dental staining. Objective assessments of enamel hypoplasia (p=1.0), hypomineralization (p=0.35), and tooth shade (p=0.2) also showed no significant differences. In a similar fashion, a blinded observational study of 39 pediatric patients exposed to doxycycline under 8 years of age (for suspected central nervous system infections) by Pöyhönen et al found no permanent tooth dental staining nor enamel hypoplasia on assessment.⁴ The average follow-up time for assessment of these permanent changes was 9.6 years.

Somewhat conversely, a review article by Wormser et al conservatively argues that the conclusion regarding the safety of doxycycline and permanent dental staining may be true but premature.⁵ The review argued that the 21-day course of doxycycline recommended for certain disease treatments such as Lyme disease has not been fully assessed and that it therefore should be withheld if there are safer, equally effective alternatives.

Conclusion

Currently, the overall data are limited, but we are unable to find any studies that demonstrate an association between doxycycline administration in children younger than 8 years of age and permanent dental staining.

References

1. Wallman IS, Hilton HB. Teeth pigmented by tetracycline. Lancet. 1962;1(7234):827-829.
2. Volovitz B, Shkap R, Amir J, et al. Absence of tooth staining with doxycycline treatment in young children. Clin Pediatr (Phila). 2007;46(2):121-126.
3. Todd SR, Dahlgren FS, Traeger MS, et al. No visible dental staining in children treated with doxycycline for suspected Rocky Mountain Spotted Fever. J Pediatr. 2015;166(5):1246-1251.
4. Pöyhönen H, Nurmi M, Peltola V, et al. Dental staining after doxycycline use in children. J Antimicrob Chemother. 2017; 72(10):2887-2890.
5. Wormser GP, Wormser RP, Strle F, et al. How safe is doxycycline for young children or for pregnant or breastfeeding women? Diagn Microbiol Infect Dis. 2019;93(3):238-242.