Key Points
Question
What proportion of pediatric patients with hidradenitis suppurativa (HS) meet existing consensus-derived HS diagnostic criteria?
Findings
In this single-center, retrospective, cross-sectional study of 297 pediatric patients with physician-diagnosed HS, 127 (42.8%) did not meet all 3 major HS diagnostic criteria based on diagnostic documentation. Of these patients, 122 (96.1%) did not meet the recurrence interval criterion (≥2 lesions within 6 months).
Meaning
The results of this study suggest that pediatric patients seeking a diagnosis of HS may experience disease recurrence less frequently than required by existing diagnostic criteria.
This cross-sectional study examines the proportion of pediatric patients with hidradenitis suppurativa who meet existing consensus-derived diagnostic criteria.
Abstract
Importance
Hidradenitis suppurativa (HS) is associated with considerable diagnostic delay. Although most patients report adolescent onset, existing HS diagnostic criteria may not adequately capture disease in pediatric populations.
Objectives
To determine the proportion of physician-diagnosed pediatric patients with HS who met diagnostic criteria, and describe demographics, disease characteristics, and diagnostic patterns among pediatric patients with HS.
Design, Setting, and Participants
In this retrospective, cross-sectional study, electronic medical records from 2 sites of a single academic tertiary care center were included. Eligible patients were those born after January 1, 1993, and assigned International Classification of Diseases, Ninth and Tenth Revisions (ICD-9/10) codes for HS (ICD-9 705.83/ICD-10 L73.2) between January 1, 2012, and July 1, 2021. Patients were excluded if they were older than 18 years at diagnosis, had inaccessible diagnostic visit notes, or were unintentionally assigned an HS ICD code.
Exposures
Pediatric patients with HS.
Main Outcomes and Measures
Fulfillment of diagnostic criteria in pediatric patients with HS.
Results
A total of 297 adolescents with HS were included in the study; 123 patients were female (78.1%), 78 self-identified as Black (26.3%), and 116 self-identified as Hispanic (39.1%). The median (IQR) age at diagnosis was 14.0 (13.0-16.0) years. Documentation from the diagnostic visit demonstrated that 127 (42.8%) patients did not meet all 3 major HS diagnostic criteria. Of these patients, 122 (96.1%) did not meet the recurrence interval criterion (≥2 lesions within 6 months). Overall, 96 patients who did not meet the recurrence interval criterion had documentation from additional visits in the health system; 59 (61.5%) had documentation of 1 or more additional lesions consistent with HS. Review of these additional records demonstrated that 26 of these 59 (44.1%) patients met the recurrence interval criterion after diagnosis, and 44 (74.6%) had recurrent lesions within a 1-year interval (median, 6.5 months; interquartile range, 3.5-12.2 months). Medical chart review was conducted from November 22, 2021, to January 12, 2022. Analysis was conducted from January 12, 2022, to January 15, 2022.
Conclusions and Relevance
Overall, 118 (40%) of 297 pediatric patients with HS in this retrospective cross-sectional study did not meet all major diagnostic criteria at the time of diagnosis, largely due to failure to fulfill the 6-month recurrence interval criterion. Future studies are needed to determine the appropriate recurrence interval to facilitate timely diagnosis and promote clinical trial eligibility for pediatric patients with HS.
Introduction
Hidradenitis suppurativa (HS) is a disfiguring and debilitating chronic inflammatory skin disease with common onset in adolescence.1 Due to clinician underrecognition and misdiagnosis,2,3 patients with HS experience a mean diagnostic delay of 2 to 7 years.3,4 Consequences of diagnostic delay for patients with HS of all ages include possible disease progression and delayed medical and procedural interventions.5,6 In addition, diagnostic delay hinders screening and treatment of HS-associated comorbidities and functional and social impairment.3,7 Therefore, timely diagnosis is crucial to the overall health and well-being of patients with HS .
Consensus-derived diagnostic criteria exist to guide accurate clinical diagnosis.8 Applied retrospectively, these criteria confirmed diagnosis in 89.6% of adult patients assigned HS International Classification of Diseases, Ninth and Tenth Revisions (ICD-9/10) codes.9 However, these criteria have not been evaluated in pediatric patients (children and adolescents).
To determine the utility of existing HS diagnostic criteria in pediatric patients, we aimed to determine the proportion of physician-diagnosed pediatric patients with HS who met diagnostic criteria. Secondary objectives included describing demographics, disease characteristics, and diagnostic patterns among pediatric patients with HS.
Methods
In this retrospective cross-sectional study of electronic medical records at a single academic tertiary care center, we identified patients born after January 1, 1993, and assigned an HS ICD-9/10 code (ICD-9 705.83/ICD-10 L73.2) between January 1, 2012, and July 1, 2021. Exclusion criteria included: age 18 years or older at diagnosis, inaccessible diagnostic visit notes, or unintentionally-assigned HS ICD-9/10 code. Physician assessment was considered the diagnostic gold standard. Ethics approval was obtained from the University of California, San Francisco institutional review board, which waived written informed consent for collection of deidentified, historical, and retrospective electronic medical record data.
We reviewed documentation from the diagnostic visit, defined by the first-recorded HS ICD-9/10 code, to determine the diagnosing physician’s specialty, patient characteristics, and fulfillment of all 3 major HS diagnostic criteria required for diagnosis, including (1) typical lesion, (2) typical location, and (3) recurrence (≥2 episodes within 6 months).8 Minor criteria of (family history of HS and absence of culturable pathogens/presence of normal skin flora) supported, but did not establish, an HS diagnosis. For patients who did not have recurrence documented in their diagnostic note, complete records were reviewed to ascertain documented history of lesions consistent with HS before and after the diagnostic visit.
We used descriptive statistics to characterize the study population and Fisher exact test for comparisons using STATA statistical software (version 17.0, STATA Corp). The University of California, San Francisco, institutional review board approval was obtained.
Results
Of 453 identified patients, we excluded 84 diagnosed at 18 years or older, 62 with inaccessible clinical data, and 10 with unintentionally-assigned HS ICD-9/10 codes. Of the remaining 297 patients, 232 were female (78.1%) and self-identified as Hispanic (n = 116, 39.1%) or Black (n = 78, 26.3%). Thirty-nine of 73 (53.4%) patients with documented Hurley staging had moderate or severe disease at diagnosis (Table). Oral antibiotics were the most common treatment prior to diagnosis (92/297, 31.0%); 69 (23.2%) patients were never treated, and no patients received biologics.
Table. Patient Demographic and Clinical Characteristics.
| Characteristics | No. (%) |
|---|---|
| Total | 297 |
| Demographic characteristics | |
| Age at onset, median, (IQR), y | 14.0 (13.0-16.0) |
| Diagnostic delay, median, (IQR), y | 1.3 (0.3-3.0) |
| Female sex, No. (%) | 232 (78.1) |
| Race/ethnicity | |
| Asian | 12 (4.0) |
| Black | 78 (24.3) |
| Hispanic | 116 (39.1) |
| Native American/Alaska Native | 3 (1.0) |
| Native Hawaiian/Pacific Islander | 4 (1.4) |
| White | 36 (12.1) |
| Unknown | 48 (16.2) |
| Clinical characteristics at diagnosis | |
| Hurley stage (n = 73) | |
| 1 | 34 (46.6) |
| 2 | 28 (38.4) |
| 3 | 11 (15.1) |
| Body sites affected, median (IQR) | 1 (1-2) |
| Affected body sites (n = 519) | |
| Axillae | 229 (44.1) |
| Groin | 126 (24.3) |
| Chest | 52 (10.0) |
| Buttocks | 51 (9.8) |
| Thighs | 34 (6.6) |
| Abdomen | 18 (3.5) |
| Back | 8 (1.5) |
| Scalp | 1 (0.2) |
| Body mass index, median (IQR) | 30.4 (24.7-35.1) |
| Fulfillment of minor criteria | |
| Family history (n = 122) | 43 (35.2) |
| Sterile or normal skin culture (n = 49) | 32 (65.3) |
| Initial diagnosing specialty | |
| Pediatric dermatology | 127 (42.8) |
| Pediatrics | 77 (25.9) |
| Emergency medicine | 42 (14.1) |
| Pediatric surgery | 18 (6.1) |
| Infectious disease | 7 (2.4) |
| Plastic surgery | 5 (1.7) |
| Other | 21 (7.1) |
| Previous treatments | |
| Oral antibiotics | 92 (31.0) |
| Topical antibiotics | 57 (19.2) |
| Antiseptic wash | 34 (11.5) |
| Incision and drainage | 32 (10.8) |
| Biologics | 0 |
| None | 69 (23.2) |
| Other | 13 (4.4) |
Major diagnostic criteria were fulfilled in 170 of the 297 (57.2%) patients based on diagnostic visit documentation. Of the 127 (42.8%) patients who did not fulfill HS diagnostic criteria based on diagnostic visit documentation, 4 did not have a typical lesion, 3 did not have a typical affected location, and 122 (96.1%) failed to meet the recurrence interval criterion (3 patients did not meet the recurrence interval and typical lesion criteria) (Figure 1).
Figure 1. Fulfillment of Hidradenitis Suppurativa (HS) Diagnostic Criteria.
More than half of identified patients had a diagnostic visit note with evidence of HS diagnostic criteria fulfillment. Of those who did not, 4 did not have a typical lesion (2 had axillary verrucous hyperkeratotic plaques, 1 had axillary induration alone, and 1 had papules that progressed from gluteal cleft to arms and face), 3 did not have a lesion in a typical location (scalp, posterior neck, or anterior thighs only), and most did not have a documented lesion consistent with HS within the 6-month recurrence interval. Complete medical record review revealed that 9 patients without evidence of recurrence in their diagnostic note had evidence of recurrence prior to their diagnostic visit. Therefore, 179 (60.3%) patients met diagnostic criteria at time of diagnosis.
aThree patients did not meet both the recurrence and typical lesion criteria.
We reviewed complete medical records of patients who did not have documentation of recurrence in the diagnostic note. Overall, 68 (70.1%) of the 96 patients who had additional visits in our health system had 1 or more additional lesions consistent with HS documented before or after diagnosis. Nine of these patients had a lesion consistent with HS documented 6 or fewer months before diagnosis; thus, these patients fulfilled HS diagnostic criteria despite the absence of recurrence documentation in the diagnostic note. Together, we determined that HS diagnostic criteria were fulfilled in 179 (60.3%) of the 297 patients at the time of diagnosis.
To assess recurrence intervals in this patient population, we calculated the duration between all documented consecutive lesions among the remaining 59 patients who did not meet the recurrence interval criterion prior to diagnosis. Patients attended follow-up appointments at a median (IQR) interval of 4.3 (2.8-6.6) months. Overall, 26 (44.1%) of these 59 patients met the 6-month recurrence interval criterion after diagnosis, and 44 (74.6%) had recurrent lesions within a 1-year interval (median, 6.5 months; IQR, 3.5-12.2 months) (Figure 2).
Figure 2. Interval Between Lesions Consistent With Hidradenitis Suppurativa (HS) for Patients Without 2 or More Documented Lesions Within a 6-Month Interval at HS Diagnostic Visit.
The median lesion interval was 6.5 months among 59 patients. Overall, 44 of 59 (75%) patients experienced recurrent lesions within 12.2 months, whereas 53 (90%) experienced recurrent lesions within 22.1 months.
Pediatric dermatology was the initial diagnosing specialty in 127 (42.8%) of all 297 cases (Table). Patients diagnosed by a dermatologist were more likely to have documented fulfillment of all major diagnostic criteria compared with those diagnosed by nondermatologists (86 [67.7%] of 127 vs 84 [49.4%] of 170; P = .002).
Discussion
Overall, this retrospective study found that 118 of 297 (40%) pediatric patients diagnosed with HS did not appear to meet consensus-derived diagnostic criteria,8 primarily due to the 6-month recurrence interval criterion. Although 26 of 59 (44.1%) patients who did not initially meet the recurrence criterion and had additional clinical encounters went on to experience recurrence within a 6-month interval, most experienced recurrence less frequently. A 12-month recurrence interval would have enabled 214 (72.1%) of 297 patients to fulfill diagnostic criteria. Given the limited literature on pediatric HS diagnostics, this finding suggests the possibility that the existing HS diagnostic criteria may not support accurate and timely diagnosis of HS in pediatric populations. Poorly suited diagnostic criteria may also hinder sufficient recruitment of pediatric patients into therapeutic clinical trials, thus limiting access to novel treatments.
In this study, patients diagnosed by pediatric dermatologists were more likely to fulfill diagnostic criteria than those who were not. This may reflect referral bias, limited awareness of HS and its diagnostic criteria or incomplete documentation of diagnostic criteria among other specialties.10 Because pediatric patients with HS present to various specialties,11 increasing awareness of HS beyond the dermatology setting is key to minimizing diagnostic delay and delayed therapy. For example, in this study, Hurley stage 2 and 3 HS, corresponding with moderate-to-severe disease, was documented in more than half of patients with documented Hurley staging, none of whom had received adalimumab, the only approved treatment for moderate-to-severe disease for patients aged 12 years or older since 2018.
Diagnostic delay has significant, long-lasting ramifications for patients, including increased health care utilization costs and increased systemic comorbidities, including depression.5,12 Depression rates among adolescents with HS are 2-times greater than the general adolescent population.7 In addition, patients with HS who experienced prolonged diagnostic delay were more likely to express mistrust of medical professionals and disengage from care.13
Limitations
Limitations of this study include its retrospective, single-center design and reliance on clinician documentation. Recurrence may be underdocumented due to limited physician awareness of HS diagnostic criteria, physician variability in medical documentation, and disease follow-up outside of our institution. Nonetheless, as one of the largest and most racially and ethnically diverse studies in the pediatric literature to our knowledge, our findings contribute to the understanding of pediatric HS diagnostics in a representative patient population.
Conclusions
Overall, this retrospective study found that 188 of 279 (40%) pediatric patients with HS did not fulfill all diagnostic criteria based on their diagnostic visit note, largely due to failure to fulfill the recurrence criterion. Future prospective studies are needed to determine if revisions to the HS diagnostic criteria are needed to facilitate timely HS diagnosis in a pediatric population.
References
- 1.Naik HB, Paul M, Cohen SR, Alavi A, Suàrez-Fariñas M, Lowes MA. Distribution of self-reported hidradenitis suppurativa age at onset. JAMA Dermatol. 2019;155(8):971-973. doi: 10.1001/jamadermatol.2019.0478 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Kirby JS, Zaenglein AL. Recognizing the effects and disparities of pediatric hidradenitis suppurativa. JAMA Dermatol. 2021;157(4):379-380. doi: 10.1001/jamadermatol.2020.5434 [DOI] [PubMed] [Google Scholar]
- 3.Liy-Wong C, Kim M, Kirkorian AY, et al. Hidradenitis suppurativa in the pediatric population: an international, multicenter, retrospective, cross-sectional study of 481 pediatric patients. JAMA Dermatol. 2021;157(4):385-391. doi: 10.1001/jamadermatol.2020.5435 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Saunte DM, Boer J, Stratigos A, et al. Diagnostic delay in hidradenitis suppurativa is a global problem. Br J Dermatol. 2015;173(6):1546-1549. doi: 10.1111/bjd.14038 [DOI] [PubMed] [Google Scholar]
- 5.Kokolakis G, Wolk K, Schneider-Burrus S, et al. Delayed diagnosis of hidradenitis suppurativa and its effect on patients and healthcare system. Dermatology. 2020;236(5):421-430. doi: 10.1159/000508787 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Riis PT, Saunte DM, Sigsgaard V, et al. Clinical characteristics of pediatric hidradenitis suppurativa: a cross-sectional multicenter study of 140 patients. Arch Dermatol Res. 2020;312(10):715-724. doi: 10.1007/s00403-020-02053-6 [DOI] [PubMed] [Google Scholar]
- 7.McAndrew R, Lopes FCPS, Sebastian K, Diaz LZ. Quality of life in hidradenitis suppurativa: A cross-sectional study of a pediatric population. J Am Acad Dermatol. 2021;84(3):829-830. doi: 10.1016/j.jaad.2020.09.072 [DOI] [PubMed] [Google Scholar]
- 8.Zouboulis CC, Del Marmol V, Mrowietz U, Prens EP, Tzellos T, Jemec GBE. Hidradenitis suppurativa/acne inversa: criteria for diagnosis, severity assessment, classification and disease evaluation. Dermatology. 2015;231(2):184-190. doi: 10.1159/000431175 [DOI] [PubMed] [Google Scholar]
- 9.Kim GE, Shlyankevich J, Kimball AB. The validity of the diagnostic code for hidradenitis suppurativa in an electronic database. Br J Dermatol. 2014;171(2):338-342. doi: 10.1111/bjd.13041 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Martins DB, Ayanruoh L, Paul M, Shukla N, Naik HB. Hidradenitis suppurativa publications are sparse in frontline specialties. Br J Dermatol. 2020;183(4):770-771. doi: 10.1111/bjd.19131 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Hallock KK, Mizerak MR, Dempsey A, Maczuga S, Kirby JS. Differences between children and adults with hidradenitis suppurativa. JAMA Dermatol. 2021;157(9):1095-1101. doi: 10.1001/jamadermatol.2021.2865 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Kirby JS, Miller JJ, Adams DR, Leslie D. Health care utilization patterns and costs for patients with hidradenitis suppurativa. JAMA Dermatol. 2014;150(9):937-944. doi: 10.1001/jamadermatol.2014.691 [DOI] [PubMed] [Google Scholar]
- 13.Howells L, Lancaster N, McPhee M, et al. Thematic synthesis of the experiences of people with hidradenitis suppurativa: a systematic review. Br J Dermatol. 2021;185(5):921-934. doi: 10.1111/bjd.20523 [DOI] [PubMed] [Google Scholar]
