Isotretinoin-unresponsive acne as a sign of a congenital disorder: a case of 21-hydroxylase deficiency.

Acne is a multifactorial and common disorder among young people and a frequent reason for dermatology consultation. When moderate-to-severe acne is not responsive to conventional treatments, oral isotretinoin is a very effective solution. However, there are cases in which this treatment fails to produce the expected results. In this case, an 18-year-old male patient with acne, unresponsive to traditional acne therapies, experienced only a partial benefit from oral isotretinoin. Endocrinology consultation and hormonal work-up revealed androgen metabolism anomalies suggestive of a non-classical form of congenital adrenal hyperplasia due to 21-hydroxylase deficiency. In this case report, the authors discuss when to suspect, how to diagnose, and how to manage similar cases.

Isotretinoin-associated acne fulminans: A multicentre, retrospective study of the European Academy of Dermatology and Venereology Task Force on Acne, Rosacea and Hidradenitis Suppurativa.

BACKGROUND: Acne fulminans (AF) is a rare severe acne entity. Although occasionally reported, it is unclear whether AF development is associated with oral isotretinoin treatment. OBJECTIVES: To investigate the occurrence of isotretinoin-associated AF, clinical characteristics and prognosis at follow-up. METHODS: An international, multicentre, retrospective study was performed in eight hospitals following the call of the EADV Task Force on Acne, Rosacea and Hidradenitis Suppurativa (ARHS). Characteristics of patients treated with isotretinoin before the development of AF (isotretinoin-associated acne fulminans, IAF) were compared with non-IAF (NAF). RESULTS: Forty-nine patients diagnosed with AF from 2008 to 2022 were included (mean age 16.4 years, SD 2.9, 77.6% male). Αrthralgias/arthritis occurred in 11 patients (22.9%). AF occurred without any previous acne treatment in 26.5% of the patients. Overall, 28 patients (57.1%) developed AF after oral isotretinoin intake (IAF group), while the remaining 21 patients (42.9%) developed AF without previous oral isotretinoin administration (NAF group). IAF occurred after a median duration of isotretinoin treatment of 45 days (IQR: 30, 90). Patients with IAF were more frequently male compared to patients with NAF (89.3% vs. 61.9%, respectively, p = 0.023). There were no differences in patients with IAF versus NAF in patient age, the duration of pre-existing acne, a family history of AF, the distribution of AF lesions or the presence of systemic symptoms or arthralgias. Regarding the management of AF, patients with IAF were treated more frequently with prednisolone (96.2%) compared to those with NAF (70%; p = 0.033) and less frequently with isotretinoin (32.1%) compared to NAF (85.7%; p < 0.001). At a median follow-up of 2.2 years, 76.4% of patients were free of AF and scarring was present in all patients. CONCLUSIONS: No specific clinical or demographic characteristics of IAF compared with NAF could be detected, a fact that does not support IAF as a district clinical entity.

Outcome Measures for the Evaluation of Treatment Response in Hidradenitis Suppurativa for Clinical Practice: A HiSTORIC Consensus Statement.

Importance: Although several clinician- and patient-reported outcome measures have been developed for trials in hidradenitis suppurativa (HS), there is currently no consensus on which measures are best suited for use in clinical practice. Identifying validated and feasible measures applicable to the practice setting has the potential to optimize treatment strategies and generate generalizable evidence that may inform treatment guidelines. Objective: To establish consensus on a core set of clinician- and patient-reported outcome measures recommended for use in clinical practice and to establish the appropriate interval within which these measures should be applied. Evidence Review: Clinician- and patient-reported HS measures and studies describing their psychometric properties were identified through literature reviews. Identified measures comprised an item reduction survey and subsequent electronic Delphi (e-Delphi) consensus rounds. In each consensus round, a summary of outcome measure components and scoring methods was provided to participants. Experts were provided with feasibility characteristics of clinician measures to aid selection. Consensus was achieved if at least 67% of respondents agreed with use of a measure in clinical practice. Findings: Among HS experts, response rates for item reduction, e-Delphi round 1, and e-Delphi round 2 surveys were 76.4% (42 of 55), 90.5% (38 of 42), and 92.9% (39 of 42), respectively; among patient research partners (PRPs), response rates were 70.8% (17 of 24), 100% (17 of 17), and 82.4% (14 of 17), respectively. The majority of experts across rounds were practicing dermatologists with 18 to 19 years of clinical experience. In the final e-Delphi round, most PRPs were female (12 [85.7%] vs 2 males [11.8%]) and aged 30 to 49 years. In the final e-Delphi round, HS experts and PRPs agreed with the use of the HS Investigator Global Assessment (28 [71.8%]) and HS Quality of Life score (13 [92.9%]), respectively. The most expert-preferred assessment interval in which to apply these measures was 3 months (27 [69.2%]). Conclusions and Relevance: An international group of HS experts and PRPs achieved consensus on a core set of HS measures suitable for use in clinical practice. Consistent use of these measures may lead to more accurate assessments of HS disease activity and life outcomes, facilitating shared treatment decision-making in the practice setting.

The Personalized Acne Treatment Tool - Recommendations to facilitate a patient-centered approach to acne management from the Personalizing Acne: Consensus of Experts.

Background: Acne, a commonly treated skin disease, requires patient-centered management due to its varying presentations, chronicity, and impact on health-related quality of life. Despite this, evidence-based clinical guidelines focus primarily on clinical severity of facial acne, omitting important patient- and disease-related factors, including ongoing management. Objectives: To generate recommendations to support patient-centered acne management, which incorporate priority and prognostic factors beyond conventional clinical severity, traditionally defined by grading the appearance and extent of visible lesions. Methods: The Personalizing Acne: Consensus of Experts consisted of 17 dermatologists who used a modified Delphi approach to reach consensus on statements regarding patient- and treatment-related factors pertaining to patient-centered acne management. Consensus was defined as ≥75% voting "agree" or "strongly agree." Results: Recommendations based on factors such as acne sequelae, location of acne, high burden of disease, and individual patient features were generated and incorporated into the Personalized Acne Treatment Tool. Limitations: Recommendations are based on expert opinion, which may differ from patients' perspectives. Regional variations in healthcare systems may not be represented. Conclusions: The Personalizing Acne: Consensus of Experts panel provided practical recommendations to facilitate individualized management of acne, based on patient features, which can be implemented to improve treatment outcomes, adherence, and patient satisfaction.

The use of ultrasound and magnetic resonance imaging in the management of hidradenitis suppurativa: a narrative review.

Hidradenitis suppurativa (HS) is a chronic, inflammatory follicular skin disease that frequently affects the apocrine gland-bearing skin of the axillary, inguinal and anogenital regions. HS has a significant impact on the psychosocial health and quality of life of patients. Diagnosis of HS is typically clinical, and relies on the ability of physicians to recognize the signs of HS. However, lesions may present at the dermal and subcutaneous skin layers, which cannot be diagnosed by clinical examination alone. Further, the complexity of the clinical presentation of HS can lead to misdiagnosis and delay of diagnosis and appropriate treatment. Imaging is an important tool that can address these issues by detecting inflammatory activity and the early subclinical and dermal features of HS, and accurately characterizing lesional morphology, thereby informing on optimal therapeutic strategies. Overall, imaging is a key tool that can be used in conjunction with clinical examination to improve the management of HS by providing additional information to physicians, and thus optimize clinical decision making. In this narrative review, we provide an overview of the general role of imaging in the management of HS, and we illustrate HS-specific applications of two pertinent imaging modalities, ultrasound and magnetic resonance imaging. Finally, based on the literature, we summarize their uses in HS and provide considerations relating to standardizing the practise of ultrasound and effectively implementing the use of imaging in the management of HS.

A New Hybrid Therapeutic Approach to Solitary Keratoacanthoma: Complete Recovery in Six Patients.

Introduction: Solitary keratoacanthoma (SKA) is generally considered as a well-differentiated form of squamous cell carcinoma, but it usually runs a benign course and a not aggressive behavior. Diagnostic criteria, prognosis, and treatment of SKA are not fully defined yet. Surgical treatment with fusiform excision represents the gold standard; nonoperative intralesional therapy of KA is uncommon but may provide a valid option in some categories of patients. Case Series Presentation: We report our experience regarding the treatment of SKA with a hybrid treatment consisting of a minimally invasive technique such as curettage followed by intralesional corticosteroid administration in the same session. Six patients affected with KA were treated ending in a complete resolution, with good esthetic outcome, no relapse after 1 year, and satisfaction of the patients. Discussion and Conclusion: The combined treatment allows us on the one hand to avoid radical surgery in selected patients and particular anatomic areas and on the other the side effects that the use of intralesional chemotherapy/immunosuppressive drugs can entail.

Which Health-Related Quality of Life Items Most Affect Acne Patients?

BACKGROUND: Health-related quality of life (HRQoL) assessment in patients with acne is recommended by several national guidelines. There are several acne-specific HRQoL instruments. OBJECTIVES: Participants of the European Academy of Dermatology and Venereology (EADV) Task Forces (TFs) on QoL and Patient Oriented Outcomes (PO) and Acne, Rosacea, and Hidradenitis Suppurativa (ARHS) agreed to scrutinize aspects of existing acne-specific HRQoL instruments for their relevance in international study. METHODS: Consensus agreement on items related to QoL was reached after an independent assessment by seven experts from the EADV TFs on QoL and PO, and a list of 97 items was prepared and proposed to a group of acne patients. In order to have data from patients to check if any important topics were overseen, another group of acne patients from participating countries was asked to list how acne influenced different aspects of their lives. RESULTS: Based on results obtained from 601 acne patients from nine countries, most of the items and topics showed low relevance for acne patients especially during the previous month or shorter time periods. Based on percentage of relevance and factor analysis, short (6 items) and long (45 items) lists of the most relevant topics were formed. CONCLUSION: Most of the items and topics from the initial list showed low relevance for acne patients. None of the identified acne-specific HRQoL instruments contain all the items that were deemed most relevant to acne patients. For this reason, participating members of the EADV TFs on QoL and PO, and ARHs are in the process of developing a new acne-specific HRQoL instrument.

Isotretinoin Laboratory Monitoring in Acne Treatment: A Delphi Consensus Study.

Importance: Although isotretinoin may rarely be associated with laboratory abnormalities such as hypertriglyceridemia, the optimal approach to laboratory monitoring is uncertain, and there is wide variation in clinical practice. Objective: To establish a consensus for isotretinoin laboratory monitoring among a diverse, international cohort of clinical and research experts in acne. Design, Setting, and Participants: Using a modified electronic Delphi process, 4 rounds of anonymous electronic surveys were administered from 2021 to 2022. For laboratory tests reaching consensus (≥70% agreement) for inclusion, questions regarding more time-specific monitoring throughout isotretinoin therapy were asked in subsequent rounds. The participants were international board-certified dermatologist acne experts who were selected on a voluntary basis based on involvement in acne-related professional organizations and research. Main Outcomes and Measures: The primary outcome measured was whether participants could reach consensus on key isotretinoin laboratory monitoring parameters. Results: The 22 participants from 5 continents had a mean (SD) time in practice of 23.7 (11.6) years and represented a variety of practice settings. Throughout the 4-round study, participation rates ranged from 90% to 100%. Consensus was achieved for the following: check alanine aminotransferase within a month prior to initiation (89.5%) and at peak dose (89.5%) but not monthly (76.2%) or after treatment completion (73.7%); check triglycerides within a month prior to initiation (89.5%) and at peak dose (78.9%) but not monthly (84.2%) or after treatment completion (73.7%); do not check complete blood cell count or basic metabolic panel parameters at any point during isotretinoin treatment (all >70%); do not check gamma-glutamyl transferase (78.9%), bilirubin (81.0%), albumin (72.7%), total protein (72.7%), low-density lipoprotein (73.7%), high-density lipoprotein (73.7%), or C-reactive protein (77.3%). Conclusions and Relevance: This Delphi study identified a core set of laboratory tests that should be evaluated prior to and during treatment with isotretinoin. These results provide valuable data to guide clinical practice and clinical guideline development to optimize laboratory monitoring in patients treated with isotretinoin.

Registries, multicentre and genome-wide association studies in hidradenitis suppurativa.

The European Hidradenitis Suppurativa Foundation (EHSF) e.V. has taken several initiatives for collaborative studies. They result from the data of the European Registry of Hidradenitis Suppurativa (ERHS) based on the knowledge obtained from the regional Northern countries (HISREG) and Italian (IRHIS) registries and the real-world data generated from claims data from insurance databases. Multicentre studies, such as the Hidradenitis Suppurativa collaborative study of subtypes (HORUS) and the Global Hidradenitis Suppurativa Atlas (GHISA), are planned to provide an ideal complement to the register studies. Most recently, the role of EHSF as a coordinator or key player is being explored in multiple genetic studies, such as a genome-wide association study (GWAS) and the exome sequencing and cellular/molecular profiling project, which will speed up gene and drug discovery in HS.

Dermoscopy, Reflectance Confocal Microscopy and Optical Coherence Tomography Features of Acne: A Systematic Review.

Noninvasive imaging techniques have recently outlined precise microscopic features of acne elementary lesions and accurate quantifications for disease severity staging and therapeutical efficacy follow-up. The aim of this review is to systematically describe current applications of dermoscopy, reflectance confocal microscopy (RCM), and optical coherence tomography (OCT) in acne vulgaris assessment and management. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. We included studies conducted on human subjects with elementary lesions of acne vulgaris, reporting assessment of the lesions with dermoscopy, RCM, and/or OCT. At present there are few large studies regarding acne and noninvasive imaging techniques, representing the main limitation of this review. Clinical examination represents the first line in acne diagnosis and treatment. However, dermoscopy, RCM, and OCT are further tools that can improve acne classification, monitoring of treatment, and pathophysiologic characterization. In the near future, dermoscopy, RCM, and OCT could become routinely used for the evaluation of acne vulgaris to provide a deeper knowledge of the disease and to guide the clinician in the prescription of tailored treatment protocols based on each patient's characteristics.

Hidradenitis suppurativa: Morphologic and vascular study of nodular inflammatory lesions by means of optical coherence tomography.

Hidradenitis suppurativa (HS) is an inflammatory disease characterized by a recurrent-remission trend and clinical lesions that range from asymptomatic to inflamed, deep-seated nodules with scarring and suppuration. The aim of our study was to identify morphologic and vascular features of HS nodules by means of dynamic optical coherence tomography (D-OCT) and to define if they are correlated to patient endotype and risk of disease progression. A set of standardized clinical pictures and D-OCT images were acquired from 57 inflammatory nodules of 40 patients affected by HS. A set of 20 clinical and D-OCT images were acquired from 20 healthy volunteers as a control group. The comparison of D-OCT features among HS and control group was analysed. The correlation between HS patient endotype and D-OCT features of the lesions was calculated. D-OCT enabled to identify vascular and morphological aspects characterizing HS nodular inflammatory lesions. In addition, several D-OCT features were significantly different among distinct disease endotypes. The characterization of HS nodular inflammatory lesions through D-OCT, corresponding to blood vessel dilation and inflammatory associated hyper-vascularization, may have important clinical consequences in the assessment of HS risk of progression, therapeutic decisions and treatment efficacy monitoring.

Seven years-experience of adalimumab therapy for Hidradenitis Suppurativa in a real-life dermatologic setting.

INTRODUCTION: Hidradenitis Suppurativa (HS) often causes severe impairment of the quality of life of patients affected, as it is characterized by recurrent relapses of inflammation and predisposes to retractive scars, with severe alteration of anatomy of the affected regions. Adalimumab is currently the only approved long-term biological therapy for this disease. MATERIAL AND METHOD: We retrospectively review the data of HS patients treated with Adalimumab at the 'Hidradenitis Suppurativa Clinic', University of Ferrara, Italy since the drug was first available to October 2020. The aim is to describe our real-life experience in a clinical outpatient service. We assessed the main demographic features, therapy duration, reasons of suspension and efficacy (evaluated by HiSCR - Hidradenitis Score) in relation to surgical procedures, hospitalization, number of areas involved by the disease and BMI > 30. We also assessed the aspects related to the use of adalimumab's biosimilar. RESULTS: Data on 76 patients, with a mean age of 38.26 ± 14.74 years and mean BMI 28.10 ± 5.92 were collected. Most of the treated patients had Hurley stage III (58/76); mean Sartorius score was 115.5 ± 55.86, mean IHS4 was 76.1 ± 44.3. A statistically significant correlation between hospitalization and cessation of adalimumab, the loss of the achievement of the HiSCR, and surgery was found. No need to do surgery was a protective factor against the failure of adalimumab treatment, meaning that the most severe cases are more likely to fail the biological therapy. CONCLUSION: New scenarios are opening up in clinical practice: the arrival of biosimilars allow greater sustainability of expenditure, while the anti-IL17 allow the patient who has failed therapy with adalimumab a valid and safe therapeutic option to be undertaken. A comprehensive care including hospitalization, a specific antibiotic therapy and surgical treatment is often mandatory to achieve a satisfactory control of the disease.

Gaps and recommendations for clinical management of truncal acne from the Personalising Acne: Consensus of Experts panel.

BACKGROUND: Truncal acne is common and burdensome for patients; however, there is paucity of evidence and guidance for the management of truncal acne. Currently, clinical practice guidelines provide very little guidance on the assessment or management of truncal acne. OBJECTIVES: To identify unmet needs in truncal acne and make recommendations to address clinical and management gaps using an international consensus. METHODS: The Personalising Acne: Consensus of Experts panel consisted of 13 dermatologists, who used a modified Delphi approach to reach a consensus on statements related to clinically relevant aspects of truncal acne evaluation and management. A consensus was defined as ≥75% of the panelists voting "agree" or "strongly agree." The voting was electronic and blinded. RESULTS: The panel identified gaps and made recommendations related to truncal acne identification, assessment, and grading; the evaluation of the impact on patients; and treatment goals and factors to be considered for its management. LIMITATIONS: The recommendations are based on expert opinion, in the absence of high-quality evidence. CONCLUSIONS: We highlighted addressing not just facial acne but also truncal acne during patient consultations. The recommendations made herein may help facilitate the care of patients who present with truncal acne, with or without facial acne.

Identifying gaps and providing recommendations to address shortcomings in the investigation of acne sequelae by the Personalising Acne: Consensus of Experts panel.

BACKGROUND: The physical sequelae of acne include erythema, hyperpigmentation, and scarring, which are highly burdensome for patients. Early, effective treatment can potentially limit and prevent sequelae development, but there is a need for guidance for and evidence of prevention-oriented management to improve patient outcomes. OBJECTIVE: To identify unmet needs of acne sequelae and generate expert recommendations to address gaps in clinical guidance. METHODS: The Personalizing Acne: Consensus of Experts panel of 13 dermatologists used a modified Delphi approach to achieve a consensus on the clinical aspects of acne sequelae. A consensus was defined as ≥75% of the dermatologists voting "agree" or "strongly agree." All voting was electronic and blinded. RESULTS: The panel identified gaps in current guidance and made recommendations related to acne sequelae. These included identification and classification of sequelae, pertinent points to consider for patient consultations, and management aimed at reducing the development of sequelae. LIMITATIONS: The recommendations are based on expert opinion and made in the absence of high-quality evidence. CONCLUSIONS: The identified gaps should help inform future research and guideline development for acne sequelae. The consensus-based recommendations should also support the process of consultations throughout the patient journey, helping to reduce the development and burden of acne sequelae through improved risk factor recognition, early discussion, and appropriate management.

The Personalised Acne Care Pathway-Recommendations to guide longitudinal management from the Personalising Acne: Consensus of Experts.

BACKGROUND: Acne is a chronic disease with a varying presentation that requires long-term management. Despite this, the clinical guidelines for acne offer limited guidance to facilitate personalized or longitudinal management of patients. OBJECTIVES: To generate recommendations to support comprehensive, personalized, long-term patient management that address all presentations of acne and its current and potential future burden. METHODS: The Personalising Acne: Consensus of Experts panel consisted of 13 dermatologists who used a modified Delphi approach to reach consensus on statements related to longitudinal acne management. The consensus was defined as ≥75% voting "agree" or "strongly agree." All voting was electronic and blinded. RESULTS: Key management domains, consisting of distinct considerations, points to discuss with patients, and "pivot points" were identified and incorporated into the Personalised Acne Care Pathway. Long-term treatment goals and expectations and risk of (or fears about) sequelae are highlighted as particularly important to discuss frequently with patients. LIMITATIONS: Recommendations are based on expert opinion, which could potentially differ from patients' perspectives. Regional variations in health care systems may not have been captured. CONCLUSIONS: The Personalised Acne Care Pathway provides practical recommendations to facilitate the longitudinal management of acne, which can be used by health care professionals to optimize and personalize care throughout the patient journey.

Anti-COVID-19 measurements for hidradenitis suppurativa patients.

The reported incidence of COVID-19 among cohorts of patients with inflammatory bowel and skin diseases under treatment with biologicals is low. Treatment may further modify disease severity as some biological modifiers, such as anakinra, are also proposed for the management of COVID-19 patients potentially providing HS patients with an advantage. The above preliminary evidence suggests that hidradenitis suppurativa (HS) does probably not provide an increased susceptibility for COVID-19 and that any susceptibility is unlikely to be modified negatively by treatment with biologicals. On the occasion of its 10th International Conference, experts of the European Hidradenitis Suppurativa Foundation e.V. have prepared a consensus statement regarding anti-COVID-19 measurements for HS patients. Based on the available knowledge, patients with HS may be vaccinated against SARS-CoV2 and patients affected by metabolic syndrome constitute a high-risk group for COVID-19 and should be vaccinated at the earliest convenient point in time. HS patients on treatment with adalimumab can be vaccinated with non-living virus anti-SARS-CoV2 vaccines. A possible suboptimal effect of the vaccine may be suspected but might not be expected universally. The management of the biological treatment in HS patients is at the discretion of the dermatologist / responsible physician.

The Association among Pyoderma Gangrenosum, Ulcerative Colitis, and Hidradenitis Suppurativa and the Syndromic Hidradenitis Suppurativa Network: A Case Report.

Hidradenitis suppurativa (HS), together with other inflammatory diseases, is involved in a syndromic network where different combinations of signs and symptoms characterize the definition. The observation of the concurrent occurrence of HS, pyoderma gangrenosum (PG), and inflammatory bowel disease (IBD), in detail ulcerative colitis (UC), led the authors to describe a new association. The patient, a 36-year-old woman, who saw IBD as the first appearing condition, shortly followed by HS and PG, was referred because of a clinical situation quickly worsening. A severe aggravation of both GI symptoms and general systemic situation total led to total colectomy. Surprisingly, shortly after the radical surgical treatment of UC, the cutaneous manifestations of HS and PG with no specific treatment almost completely disappeared suggesting the existence of a common etiopathogenetic mechanism and possibly an inductor role of UC on the other disorders. The presentation of this case offers the opportunity to deal with the fact that the resolution of one of the associated conditions may lead to the clearance of one or more of the others. It confirms a pathogenetic link between them and the pivotal role of one of them, in this case colitis.

Tetracyclines and photosensitive skin reactions: A narrative review.

Tetracyclines are a group of broad-spectrum antibiotics largely employed in infectious, dermatological and surgical fields. Some adverse events may occur during treatment, including photosensitivity reactions, which are divided in phototoxic or photoallergic. We performed a systematic search on Pubmed, Cochrane and Embase from database inception to August 9, 2020 aim to summarize all available papers on photosensitive reactions related to tetracyclines in all clinical settings where they are used on human being. On the basis of our inclusion criteria, we selected only randomized controlled trials, open comparative trials and prospective cohort studies performed on both volunteers and patients, moreover we included a pharmacovigilance register. Thirty-eight articles met inclusion criteria, describing photo-sensitive effects due to doxycycline, minocycline, tetracycline, lymecycline, sarecycline, demethylchlortetracycline, chlortetracycline and metacycline, across six diagnoses (acne, Lyme disease, Gulf Veteran Illness, adbominal aortic aneurysms, traveler's diarrhea and pterygium) and several volunteers who were deliberately exposed to natural or artificial light sources. Not all drugs belonging to tetracyclines class are available to date, moreover the studies included lacked a homogeneous design and most of them involved a scarce number of patients, including reactions induced in volunteers during photo-testing. Available data on incidence, severity and clinical relevance of tetracyclines-related photo-sensitive reactions are scarce, heterogeneous and weak. What we can extrapolate is that some tetracyclines are more often related to phototoxic skin reactions than others and some of those seem to have a very low risk of phototoxicity.

The link between hidradenitis suppurativa and phylloid hypomelanosis in partial trisomy-13 mosaicism: New evidences and further genetic/pathogenetic insights.

Partial trisomy-13 mosaicism (PT13M) is a rare condition. Among its possible associated cutaneous features, phylloid hypomelanosis (PH), characterized by leaf-like macules reminiscent of floral ornaments in the form of round or oval spots and patches and oblong lesions, is typical. Two cases of PH associated with hidradenitis suppurativa (HS) have been already reported in the literature. We report a third child with PH due to PT13M associated with HS-like lesions limited to hypomelanotic regions. We hypothesize that follicular occlusion genes may be located in the duplicated part of chromosome 13.