Early and Sustained Acne Lesion Reductions With Fixed-Dose Clindamycin Phosphate 1.2%/Adapalene 0.15%/Benzoyl Peroxide 3.1% Gel.

BACKGROUND: A once-daily, three-pronged approach using an antibiotic, antibacterial, and retinoid may provide faster acne improvement versus monotherapy or dual-combination products. This post hoc analysis compared threshold acne lesion reductions with clindamycin phosphate 1.2%/adapalene 0.15%/benzoyl peroxide 3.1% (CAB) gel—the first FDA-approved triple-combination topical acne product—to its dyads and vehicle. METHODS: Phase 2 (N=741; NCT03170388) and phase 3 (N=183; N=180; NCT04214639; NCT04214652), double-blind, 12-week studies randomized participants aged ≥9 years with moderate-to-severe acne to once-daily CAB or vehicle gel; the phase 2 study included three additional dyad gel arms. The pooled percentage of participants achieving ≥33%, ≥50%, and ≥75% reduction in inflammatory and noninflammatory acne lesions was evaluated. RESULTS: As early as week 4 in the phase 2 study, ≥33% reduction in inflammatory lesions occurred in a significantly greater percentage of CAB gel-treated participants (82.7%) than with the 3 dyads and vehicle (61.1-69.8%; P<0.05, all). These early reductions were sustained throughout the study, with significantly (P<0.05) more CAB-treated participants achieving ≥50% reduction in inflammatory lesions versus dyads and vehicle from weeks 4-12. By week 12, CAB led to substantial reductions of ≥75% in significantly more participants than dyads and vehicle (65.8% vs 49.9-51.2% and 21.6%; P<0.05, all). Similar trends were observed for noninflammatory lesions in the phase 2 study and for inflammatory and noninflammatory lesions in the phase 3 studies. CONCLUSIONS: Lesion count reductions were significantly greater with CAB versus its dyads and vehicle gel as early as week 4, with substantial reductions observed after 12 weeks of treatment. This faster-acting and sustained efficacy of CAB gel—coupled with its optimized formulation, once-daily dosing, and tolerability—may positively impact treatment adherence. J Drugs Dermatol. 2024;23(3):     doi:10.36849/JDD.7907.

Berdazimer gel for molluscum contagiosum: An integrated analysis of 3 randomized controlled trials.

BACKGROUND: An out-of-office therapeutic agent indicated for molluscum contagiosum is needed. OBJECTIVE: To assess the efficacy and safety of berdazimer gel, 10.3% (a topical, antiviral, nitric oxide-releasing medication) versus vehicle. METHODS: Berdazimer gel, 10.3% or vehicle was applied once daily to all molluscum contagiosum lesions for 12 weeks in patients ≥6 months with 3-70 mollusca. Efficacy assessment: complete lesion clearance and partial clearance at week 12. Safety and tolerability assessment: adverse events through week 24 and local skin reactions through week 12. RESULTS: There were 1598 patients enrolled (n = 917 berdazimer, n = 681 vehicle). Berdazimer was superior to vehicle at week 12 in complete clearance rates, 30.0% versus 19.8% (odds ratio, 1.75; 95% CI, 1.38-2.23, P < .001). Subgroup analyses of primary efficacy showed consistent favorable efficacy for berdazimer across most subgroups, including age, sex, baseline lesion count, and disease duration. Berdazimer provided favorable outcome for partial clearance. Application-site pain (18.7% vs 4.8% in berdazimer vs vehicle) and erythema (11.7% vs 1.3%), mostly mild to moderate, were the most common local skin reactions. LIMITATIONS: Berdazimer sodium in molluscum patients with lesions (B-SIMPLE) trials enrolled only US patients; no efficacy assessments beyond week 12. CONCLUSIONS: Berdazimer gel, 10.3% showed favorable efficacy and safety across subgroups.

Long-term Efficacy and Safety of Microencapsulated Benzoyl Peroxide Cream, 5%, in Rosacea: Results From an Extension of Two Phase III, Vehicle-controlled Trials.

Objective: We sought to assess the long-term safety and tolerability of microencapsulated benzoyl peroxide cream, 5% (E-BPO cream, 5%), in subjects with rosacea. Efficacy and tolerability have been previously demonstrated in two 12-week, randomized, double-blind, vehicle-controlled Phase III trials. Methods: In this open-label extension study (NCT03564145; clinicaltrials.gov), all subjects from the initial placebo-controlled Phase III trials could receive E-BPO cream, 5%, for up to an additional 40 weeks, up to a total of 52 weeks of E-BPO cream, 5%, exposure. If a subject was assessed at study visits as "clear" or "almost clear" using the 5-point Investigator Global Assessment (IGA) scale (IGA 0 or 1), E-BPO cream, 5%, was not dispensed. If a subject was assessed as "mild to severe" (IGA 2+), E-BPO cream, 5%, was applied daily until they reached "clear" or "almost clear." Results: The safety and tolerability profile for E-BPO cream, 5%, was similar to that reported in the Phase III studies. Five subjects (0.9%) discontinued study drug due to treatment-related adverse events, and 17 subjects (3.2%) experienced an adverse event considered related to study drug. IGA success after 40 weeks of active treatment was 66.5 percent for subjects continuing from the Phase III vehicle group (n=172) and 67.6 percent for subjects who continued Phase III E-BPO cream, 5% (n=363). The study ended early in accordance with the protocol. Limitations: Safety and tolerability of E-BPO were not compared with those of unencapsulated BPO. Conclusion: E-BPO cream, 5%, showed a favorable safety and tolerability profile during this 40-week, open-label extension study.

Efficacy and Safety of Microencapsulated Benzoyl Peroxide Cream, 5%, in Rosacea: Results From Two Phase III, Randomized, Vehicle-Controlled Trials.

Objective: A new formulation of benzoyl peroxide (E-BPO cream, 5%) entraps benzoyl peroxide (BPO) in silica microcapsules. This study assesses the efficacy, safety, and tolerability of E-BPO cream, 5%, in rosacea in two Phase III clinical trials. Methods: In two 12-week, randomized, double-blind, vehicle cream-controlled Phase III trials, 733 subjects at least 18 years old with moderate to severe rosacea were randomized (2:1) to once-daily E-BPO cream, 5%, or vehicle. Results: In Study 1, the proportion of subjects achieving IGA clear/almost clear at Week 12 was 43.5 percent for E-BPO cream, 5%, and 16.1 percent for vehicle. In Study 2, the respective values were 50.1 percent and 25.9 percent. In Study 1, the decrease in lesion count from baseline to Week 12 was -17.4 for E-BPO cream, 5%, versus -9.5 for vehicle. In Study 2, the respective values were -20.3 and -13.3 (all P<0.001). The difference was also significant at Week 2. There were no treatment-related serious adverse events; 1.4 percent of subjects (1.8% E-BPO cream, 5%, 0.4% vehicle) discontinued due to adverse events. Assessed local tolerability was found to be similar among subjects in both E-BPO and vehicle.E-BPO was not compared with unencapsulated BPO. Conclusion: E-BPO is an effective and well tolerated treatment for rosacea. Clinicaltrials.gov Identifiers: NCT03564119, NCT03448939.

Dermal sensitization, safety, and tolerability of triple-combination clindamycin phosphate 1.2%/benzoyl peroxide 3.1%/adapalene 0.15% gel from three clinical trials.

BACKGROUND: Using a three-pronged acne treatment approach-combining an antibiotic, antimicrobial agent, and retinoid-may provide greater efficacy than monad or dyad treatments. Herein are the dermal sensitization, irritation, safety, and tolerability results from phase 1 and 2 studies of fixed-dose clindamycin phosphate 1.2%/benzoyl peroxide (BPO) 3.1%/adapalene 0.15% (IDP-126) polymeric mesh gel. METHODS: Two phases 1, single-blind, vehicle-controlled dermal safety studies were conducted in healthy participants aged ≥18 years. One phase 2 (NCT03170388) double-blind, randomized, parallel-group, and vehicle-controlled study was conducted over 12 weeks in participants aged ≥9 years with moderate-to-severe acne. RESULTS: A total of 1,020 participants (IDP-126 gel, vehicle, or 1 of the 3 dyad gels [phase 2 only]) were included across the 3 studies (safety populations: n = 1,004). In the phase 1 studies, IDP-126 had no confirmed sensitization or contact dermatitis. IDP-126 (deemed "moderately irritating") was significantly less irritating than commercially available BPO 2.5%/adapalene 0.3% gel. CONCLUSIONS: The results from these three studies show that the triple-combination IDP-126 had a positive safety profile and was well tolerated in healthy participants and those with moderate-to-severe acne.

Efficacy and safety of microencapsulated benzoyl peroxide and microencapsulated tretinoin for the treatment of acne vulgaris: Results from two phase 3 double-blind, randomized, vehicle-controlled studies.

BACKGROUND: Benzoyl peroxide and tretinoin are commonly prescribed acne treatments. Historically, they have been difficult to combine in a single formulation due to chemical instability, and both medications are potentially irritating. Microencapsulation helps overcome these challenges. OBJECTIVE: Examine efficacy, safety, and tolerability of encapsulated BPO/encapsulated tretinoin (E-BPO/T) cream, 3%/0.1%. METHODS: Subjects ≥9 years old with moderate to severe acne were enrolled in 2 multicenter, double-blind, vehicle-controlled, parallel trials and randomized (2:1) to 12 weeks of once-daily E-BPO/T (n = 571) or vehicle cream (n = 287). RESULTS: E-BPO/T was significantly superior to vehicle in both studies, with more subjects achieving IGA success with E-BPO/T (38.5%/25.4%) versus vehicle (11.5%/14.7%; P < .001/P = .017). The change from baseline in inflammatory lesion count for E-BPO/T was -21.6 versus -14.8 for vehicle (P < .001) in study 1 and -16.2 versus -14.1 (P = .018) in study 2. The changes from baseline in noninflammatory lesions for E-BPO/T were -29.7 versus -19.8 for vehicle (P < .001) and -24.2 and -17.4 (P < .001) in studies 1 and 2, respectively. E-BPO/T was well tolerated in both studies. LIMITATIONS: Long-term data are not available. CONCLUSION: E-BPO/T provided statistically significant and clinically relevant improvements in IGA and inflammatory and noninflammatory lesion counts and was well tolerated in subjects with moderate to severe acne.

Impact of Crisaborole on Sleep Outcomes in Pediatric Patients with Mild-to-Moderate Atopic Dermatitis.

INTRODUCTION: Using data from three clinical trials, the effect of crisaborole treatment on sleep outcomes for pediatric patients with atopic dermatitis (AD) and their families was examined. METHODS: This analysis comprised patients aged 2 to < 16 years from the double-blind phase 3 CrisADe CORE 1 (NCT02118766) and CORE 2 (NCT02118792) studies, families of patients aged 2 to < 18 years from CORE 1 and CORE 2, and patients aged 3 months to < 2 years from the open-label phase 4 CrisADe CARE 1 study (NCT03356977), all with mild-to-moderate AD who received crisaborole ointment 2% twice daily for 28 days. Sleep outcomes were assessed via the Children's Dermatology Life Quality Index and Dermatitis Family Impact questionnaires in CORE 1 and CORE 2 and the Patient-Oriented Eczema Measure questionnaire in CARE 1. RESULTS: In CORE 1 and CORE 2, a significantly lower proportion of crisaborole-treated patients than vehicle-treated patients reported sleep disruption at day 29 (48.5% versus 57.7%, p = 0.001). The proportion of families whose sleep was affected by their child's AD in the preceding week was also significantly lower in the crisaborole group (35.8% versus 43.1%, p = 0.02) at day 29. At day 29 in CARE 1, the proportion of crisaborole-treated patients who experienced ≥ 1 night of disturbed sleep in the previous week decreased by 32.1% from baseline. CONCLUSION: These results suggest that crisaborole improves sleep outcomes in pediatric patients with mild-to-moderate AD and their families.

Atopic dermatitis (AD), also known as eczema, is a chronic skin disease that causes red or flaky skin patches that can become infected and itch. Children with AD often experience sleep disturbance, including difficulty falling asleep, restless sleep, waking up more frequently, and daytime drowsiness. Problems with sleep quality negatively impact children with AD, as well as their caregivers. Crisaborole ointment is applied to the skin and has been shown to improve the symptoms of AD in children and adults. This study examined how treatment with crisaborole affected sleep quality for children and their caregivers in three clinical trials. Children in these studies took crisaborole for 28 days. Researchers found that crisaborole treatment improved sleep in children with mild-to-moderate AD and their caregivers. This was determined using four measures. First, a smaller proportion of children who were treated with crisaborole experienced sleep disruption compared with those to whom a vehicle was applied (an ointment with no drug). Second, a smaller proportion of caregivers of children with AD who were treated with crisaborole reported effects on their sleep, compared with children to whom a vehicle was applied. Third, a smaller proportion of children with AD who were treated with crisaborole, as well as their caregivers, had ≥ 1 night per week of disturbed sleep after treatment compared with before treatment. Fourth, the caregivers of children treated with crisaborole reported significantly less exhaustion and tiredness because of the child's AD. These results suggest that treatment with crisaborole improves sleep outcomes in children with mild-to-moderate AD and their caregivers.

The efficacy and safety of burosumab in two patients with cutaneous skeletal hypophosphatemia syndrome.

Cutaneous skeletal hypophosphatemia syndrome (CSHS) is an ultra-rare mosaic disorder manifesting as skeletal dysplasia and FGF23-mediated hypophosphatemia, with some experiencing extra-osseous/extra-cutaneous manifestations, including both benign and malignant neoplasms. Like other disorders of FGF23-mediated hypophosphatemia including X-linked hypophosphatemia (XLH) and tumor-induced osteomalacia (TIO), patients with CSHS have low serum phosphorus and active 1,25-dihydroxyvitamin D levels. Current treatment options for patients with CSHS include multiple daily doses of oral phosphorus and one or more daily doses of active vitamin D analog to correct the deficits. Recently, the fully human monoclonal antibody against FGF23 burosumab received US approval for the treatment of XLH and TIO, two rare diseases characterized by FGF23-mediated hypophosphatemia leading to rickets and osteomalacia. Given the similarities between the pathobiologies of these disorders and CSHS, we investigated the impact of burosumab on two patients, one pediatric and one adult, with CSHS who participated in separate, but similarly designed trials. In both the pediatric and adult patients, burosumab therapy was well-tolerated and contributed to clinically meaningful improvements in disease outcomes including normalization of phosphorus metabolism and markers of bone health, and improvements in skeletal abnormalities, fractures, and physical function. Reported adverse events were minimal, with only mild injection site reactions attributed to burosumab therapy. Together, these findings suggest that burosumab therapy is a promising therapeutic option for patients with CSHS.

The New Face of Preadolescent and Adolescent Acne: Beyond the Guidelines.

Acne is a highly prevalent condition, affecting the majority of people at some point in their lifetimes, most often during adolescence. Acne has also become increasingly common among preadolescents (aged ≥7 to ≤12 years old).Acne is often treated in primary care settings by nondermatologists. The most recent acne guidelines were published in 2016; since then, there have been important developments in the acne treatment landscape. Familiarity with these options is important for physicians who manage patients with acne.The Preadolescent Acne Roundtable group of dermatologists was convened in July 2019 to support discussion around modernizing the approach to treatment and evaluation of preadolescent acne. During a face-to-face meeting, 5 key areas requiring careful communication emerged: acne pathophysiology, specifically the role of hormones; psychological aspects of acne; management of acne in younger patients; acne in skin of color; and evaluation of clinical success.This roundtable report describes these 5 focus areas, with the aim of empowering primary care physicians to refine the care they provide for patients with acne. This report can help bridge the information gap until new acne treatment guidelines are published.

Psoriasiform dermatitis during dupilumab treatment for moderate-to-severe atopic dermatitis in children.

BACKGROUND/OBJECTIVES: Psoriasiform eruptions after initiation of dupilumab have been previously described in adults. This report details the risk of developing or unmasking psoriasiform eruptions after initiation of dupilumab in children. METHODS: Records of patients ≤18 years of age with atopic dermatitis who developed psoriasiform dermatitis during treatment with dupilumab were reviewed retrospectively. RESULTS: Six children, 4-18 years of age, on dupilumab for severe atopic dermatitis developed new-onset psoriasiform dermatitis at a median duration of 8 months (range, 6-12 months) after dupilumab initiation. Typical locations of psoriasis were involved (face, scalp, trunk, and extensor extremities). The majority showed clearance or near clearance with the use of medium-strength to potent topical corticosteroid ointments and 83% continued use of the dupilumab. A 7th patient had psoriasis, in addition to severe atopic dermatitis, and the psoriasis was unmasked by its failure to respond to dupilumab. CONCLUSION: Although unusual, psoriasiform lesions can appear during effective treatment with dupilumab for atopic dermatitis, potentially reflecting a shift toward cutaneous IL-23/TH 17 pathway activation with dupilumab-induced suppression of type 2 immunity.

Seeing the Treatment of Psoriasis in a New Light: A Novel Medical Device Utilizing Localized Coal Tar and Narrowband UVB for Targeted Treatment of Plaque Psoriasis.

Given the high costs of systemic psoriasis therapies, studies have also shown that phototherapy achieves significant cost savings by replacing or delaying drug-based systemic treatment in patients with moderate to severe disease. However, this modality is often underutilized mainly due to the lack of phototherapy treatment centers across the country. Home phototherapy was designed to fill this treatment gap and allow patients to be treated with phototherapy despite living in areas that may not have a formal treatment facility. Inspired by the Goeckerman regimen, a preliminary pilot study showed that a novel, home phototherapy device utilizing a mobile phone-controlled L.E.D UVB light source and an occlusive hydrogel patch containing coal tar was superior to control as well as both NB-UVB alone and a coal tar dressing alone.Visit the Psoriasis Resource Center for more on this topic.

Erethism Mercurialis and Reactions to Elemental Mercury.

Mercury is an underrecognized cause of heavy metal poisoning. Typically, mercury exposure occurs though consumption of methylmercury in seafood or acute inhalation of elemental mercury vapors, with other routes of exposure being uncommon. We describe a case of mercury toxicity resulting from intentional injection of liquid mercury into the right antecubital fossa in a suicide attempt. Mercury poisoning may present with characteristic neuropsychologic signs and symptoms. Increasing anxiety, depression, tremors, irritability, and difficulty concentrating coupled with blood mercury levels higher than 100 µg/L and urine mercury levels of 477 µg/g led to the diagnosis of erethism mercurialis, a constellation of neuropsychologic signs and symptoms including restlessness, irritability, insomnia, emotional lability, difficulty concentrating, and impaired memory. Skin reactions associated with contact to elemental mercury are rare. However, this case presented with a mercury granuloma. Hives and dermatitis have been observed following accidental contact with inorganic mercury compounds.

Safety, Pharmacokinetics, and Efficacy of Efinaconazole 10% Topical Solution for Onychomycosis Treatment in Pediatric Patients.

BACKGROUND: Pediatric onychomycosis management is challenging as there are limited treatment options. The objective of this study was to evaluate efinaconazole 10% topical solution in children with onychomycosis. METHODS: This phase 4, multicenter, open-label study (NCT02812771) evaluated safety, pharmacokinetics (PK), and efficacy of efinaconazole 10% topical solution in pediatric participants (6-16 years). Efinaconazole was administered once daily for 48 weeks, with a 4-week posttreatment follow up. Participants had culture-positive, mild-to-severe distal lateral subungual onychomycosis affecting at least 20% of at least 1 great toenail. The PK subset included participants 12-16 years with moderate-to-severe onychomycosis affecting at least 50% of each great toenail and onychomycosis in at least 4 additional toenails. RESULTS: Of 62 enrolled participants, 60 were included in the safety population and 17 in the PK population. Efinaconazole 10% topical solution was well tolerated. The concentration-time profiles for efinaconazole and its major metabolite were relatively stable, with only minor fluctuations during the 24-hour dosing interval. Systemic exposure to efinaconazole was low. By week 52, 65.0% of participants achieved mycologic cure, with a 36.7% mycologic cure rate observed as early as week 12. A total of 40.0% of participants achieved complete cure, 50.0% achieved clinical efficacy, and 88.3% achieved fungal cure by week 52. CONCLUSION: Efinaconazole was safe and efficacious in pediatric participants with mild-to-severe onychomycosis, with improved mycologic cure and complete cure rates compared with adults from two 52-week studies. J Drugs Dermatol. 2020;19(9):867-872. doi:10.36849/JDD.2020.5401.

Systemic immunosuppressive therapy for inflammatory skin diseases in children: Expert consensus-based guidance for clinical decision-making during the COVID-19 pandemic.

BACKGROUND/OBJECTIVES: The COVID-19 pandemic has raised questions about the approach to management of systemic immunosuppressive therapies for dermatologic indications in children. Change to: Given the absence of data to address concerns related to SARS-CoV-2 infection and systemic immunosuppressive therapies in an evidence-based manner, a Pediatric Dermatology COVID-19 Response Task Force (PDCRTF) was assembled to offer time-sensitive guidance for clinicians. METHODS: A survey was distributed to an expert panel of 37 pediatric dermatologists on the PDCRTF to assess expert opinion and current practice related to three primary domains of systemic therapy: initiation, continuation, and laboratory monitoring. RESULTS: Nearly all respondents (97%) reported that the COVID-19 pandemic had impacted their decision to initiate immunosuppressive medications. The majority of pediatric dermatologists (87%) reported that they were pausing or reducing the frequency of laboratory monitoring for certain immunosuppressive medications. In asymptomatic patients, continuing therapy was the most popular choice across all medications queried. The majority agreed that patients on immunosuppressive medications who have a household exposure to COVID-19 or test positive for new infection should temporarily discontinue systemic and biologic medications, with the exception of systemic steroids, which may require tapering. CONCLUSIONS: The ultimate decision regarding initiation, continuation, and laboratory monitoring of immunosuppressive therapy during the pandemic requires careful deliberation, consideration of the little evidence available, and discussion with families. Consideration of an individual's adherence to COVID-19 preventive measures, risk of exposure, and the potential severity if infected must be weighed against the dermatological disease, medication, and risks to the patient of tapering or discontinuing therapies.

Clues to primary vismodegib resistance lie in histology and genetics.

Basal cell carcinoma (BCC) is the most common human malignant neoplasm. However, there are multiple BCC subtypes that share clinical features while demanding different management. We present a case of a woman with hundreds of BCCs throughout her body that were resistant to vismodegib and without other features of basal cell nevus syndrome. Histological results of biopsies taken from various sites revealed three lesions characteristic of infundibulocystic BCCs (IBCCs) and two BCCs. Paired whole-exome sequencing performed using DNA isolated from blood and one of her IBCCs uncovered a germline heterozygous SUFU (Suppressor of Fused) mutation. The downstream location of SUFU in the hedgehog pathway explains why its mutation results in IBCCs that will not respond to any therapeutics that target upstream components of SUFU These results capture the significance of histological and genetic analysis in directing treatment.

Microencapsulated Benzoyl Peroxide and Tretinoin for the Treatment of Acne Vulgaris: Results from a Phase 2 Multicenter, Double-Blind, Randomized, Vehicle-Controlled Study.

This phase 2, 12-week, multicenter, randomized, double-blind, active- and vehicle-controlled (VC), parallel-group trial assessed the efficacy and safety of silica encapsulated benzoyl peroxide BP (E-BP), two concentrations of silica encapsulated tretinoin (E-ATRA) and their combinations (TWIN high and low) vs VC in 726 males and females ≥9 years of age with moderate-to-severe inflammatory facial acne. The co-primary efficacy endpoints were Investigators Global Assessment (IGA) success rate ("clear" or "almost clear") and changes from baseline in inflammatory and non-inflammatory lesion counts. TWIN high and low were each significantly superior vs VC for IGA success at 12 weeks (39.7% and 27.4%, respectively, vs 12.3%, P < 0.001 and P < 0.01). TWIN high and low resulted in mean reductions in inflammatory lesions of -16.9 (64%) and -17.0 (60.8%) vs -11.5 (42%) for VC. Reductions in non-inflammatory lesions were -23.7 for TWIN low (54.9%) and -23.6 for TWIN high (53.3%) vs -13.7 (32.4%) for VC (all P < 0.001 vs VC). Results for TWIN were also numerically superior to E-BP and E-ATRA. All treatments were safe with comparable skin tolerability. The significant superiority of both combinations over VC and numerical superiority over E-BP and E-ATRA were achieved without an increase in adverse events or reduced skin tolerability.

Atypical presentations of congenital hemangiomas: Extending the clinical phenotype.

BACKGROUND/OBJECTIVES: Congenital hemangiomas (CH) are a group of benign vascular tumors that are present at birth and exhibit variable involution during infancy. Congenital hemangiomas that do not involute are typically solitary patch or plaque-type tumors that grow proportionally with somatic growth. We report a case series of 9 patients with persistent CH, which exhibited uncommon features including segmental involvement, recurrent or severe pain, or growth via volumetric increase in size or apparent increased extent of anatomic involvement over time. METHODS: Via retrospective chart review, we included patients with persistent CH and atypical presentations. Available data regarding clinical characteristics, natural history, histopathology, imaging, and genetic tests were collected. RESULTS: Data on 9 patients were collected, including 7 noninvoluting CH and 2 partially involuting CH. Three of the 9 cases had segmental distribution, 6 had apparent growth or clinical evolution, and 4 were symptomatic with pain. One also had marked localized intravascular coagulopathy. CONCLUSIONS: Ongoing or recurrent pain and large extent of anatomic involvement can be features of CH, albeit uncommon ones, and can pose both diagnostic and management challenges. Tissue genomic studies can offer a novel tool for CH diagnosis.