INTRODUCTION
Post-inflammatory hyperpigmentation is a common sequela of acne.1 Although oral tetracyclines (TCNs) are widely prescribed for acne given their anti-inflammatory properties, they independently increase the risk of hyperpigmentation, particularly in the setting of sun exposure.2 Nevertheless, the interaction between TCN-associated hyperpigmentation and seasonal variation in sun exposure in the setting of acne has not been rigorously explored. Here, we examine seasonality in hyperpigmentation incidence in addition to Google search trends.
We queried the Massachusetts General Brigham and Women’s Hospital registry (1992-2022) for acne patients using a validated algorithm (n=50,471).3,4 Patients who had ever received an International Classification of Diseases (ICD) code for melasma (L81.1, n=978) or who had received an ICD code for hyperpigmentation (709.00, 709.09, L81.0, L81.4, L81.8, L81.9) prior to their first acne diagnosis were excluded (n=4,315). Patients who had ever received isotretinoin were also excluded, given the higher disease severity and differential drug effects in this population (n=6,537). We identified cohorts who were prescribed doxycycline (n=546) or minocycline (n=148) monotherapy within one year of acne diagnosis and calculated the incidence of new-onset hyperpigmentation at least two weeks after the first TCN prescription, comparing against a cohort of acne patients who were never prescribed a TCN (n=2,136).5 Google Trends is a tool that provides real-time data about Google search frequencies from 2004 onwards. Relative search volume for a given term is represented by the search volume index (SVI), which ranges from 0 to 100.6 We extracted and combined SVI data for the terms "hyperpigmentation" and
We queried the Massachusetts General Brigham and Women’s Hospital registry (1992-2022) for acne patients using a validated algorithm (n=50,471).3,4 Patients who had ever received an International Classification of Diseases (ICD) code for melasma (L81.1, n=978) or who had received an ICD code for hyperpigmentation (709.00, 709.09, L81.0, L81.4, L81.8, L81.9) prior to their first acne diagnosis were excluded (n=4,315). Patients who had ever received isotretinoin were also excluded, given the higher disease severity and differential drug effects in this population (n=6,537). We identified cohorts who were prescribed doxycycline (n=546) or minocycline (n=148) monotherapy within one year of acne diagnosis and calculated the incidence of new-onset hyperpigmentation at least two weeks after the first TCN prescription, comparing against a cohort of acne patients who were never prescribed a TCN (n=2,136).5 Google Trends is a tool that provides real-time data about Google search frequencies from 2004 onwards. Relative search volume for a given term is represented by the search volume index (SVI), which ranges from 0 to 100.6 We extracted and combined SVI data for the terms "hyperpigmentation" and
