The prevalence of familial rosacea is nearly 70% when extending to 6 generations, investigators reported in a study published in the Journal of Clinical and Aesthetic Dermatology.
The retrospective, observational study assessed familiarity and interfamilial transmission up to 6 generations in patients with rosacea.
A total of 130 adult patients (mean age, 49.3 ± 18.6 years; range, 18-85 years; 93 women) were consecutively enrolled from a clinic in Italy from June 2018 to June 2019. Most of the affected relatives were also clinically examined, and photos were obtained for those not available for consultation.
Regarding familiarity, 64 probands from 130 patients (49.2%) were positive for at least 1 family member. A statistically significant association was observed between familial rosacea and fixed centrofacial erythema with or without telangiectasias with papules/pustules lesions (P =.005) and alcohol consumption (P =.01).
Among the probands after familial anamnestic assessment of the whole kindred, 90 affected relatives (69.2%) were identified. A statistically significant association was observed between phymatous changes and male sex (P =.0001).
Vertical transmission of rosacea inheritance was recorded in 45 (70.3%) probands, horizontal in 11 (17.2%), and combined in 8 (12.5%). Maternal lineage was predominant vs paternal (29/45.3% vs 21/32.9%) in the vertical transmission group. In the horizontal transmission group of 13 relatives, 2 pairs of fraternal twins were identified, and 21 relatives were involved in combined horizontal/vertical transmission.
The investigators noted that their findings are limited by the sample size.
Based on their data, “the prevalence of familial rosacea was 69.2%, with a ratio of patients positive for familiarity/affected relatives equal to 1:1.4,” stated the study authors. They believe that “the prevalence of rosacea familiarity is underestimated and that a more accurate investigation among multiple family generations is advisable. Extending the search to all potential affected parents or offspring of rosacea patients with a positive family history can promote early diagnosis aimed at the adoption of correct therapeutic intervention and educational programs to prevent the exposure to triggering or exacerbating factors.”
Dall’Oglio F, Fusto C, Micali G. Intrafamilial transmission of rosacea spanning six generations: a retrospective observational study. J Clin Aesthet Dermatol. 2022;15(2):35-39. PMID: 35309876