A novel digital PCR assay for detection and comprehensive characterization of Molluscum contagiosum virus genotypes MOCV1, MOCV2, and MOCV3 and recombinant lineages.

Molluscum contagiosum virus (MOCV) is an important human pathogen causing a high disease burden worldwide. It is the last exclusively human-infecting poxvirus still circulating in its natural reservoir-a valuable model of poxviral evolution. Unfortunately, MOCV remains neglected, and little is known about its evolutionary history and circulating genomic variants, especially in non-privileged countries. The design weaknesses of available MOCV detection/genotyping assays surfaced with recent accumulation of abundant sequence information: all existing MOCV assays fail at accurate genotyping and capturing sub-genotype level diversity. Because complete MOCV genome characterization is an expensive and labor-intensive task, it makes sense to prioritize samples for whole-genome sequencing by diversity triage screening. To meet this demand, we developed a novel assay for accurate MOCV detection and genotyping, and comprehensive sub-genotype qualification to the level of phylogenetic groups (PGs). The assay included a novel set of oligonucleotide primers and probes, and it was implemented using digital polymerase chain reaction (dPCR). It offers sensitive, specific, and accurate detection, genotyping (MOCV1-MOCV3), and PG qualification (PG1-6) of MOCV DNA from clinical samples. The novel dPCR assay is suitable for MOCV diversity triage screening and prioritization of samples for complete MOCV genome characterization.

[Skin reactions related to molluscum contagiosum infection]. / Reacciones cutáneas relacionadas a la infección por molusco contagioso.

Molluscum contagiosum (MC) is a common viral infection in children, immunocompromised, and sexually active adults. Its usual clinical presentation is 2-5 mm, whitish or skin-colored papules, with a shiny surface and central umbilication, generally clustered and randomly distributed over the skin surface. Dermoscopy reveals yellowish-white polylobulated structures with peripheral telangiectasia. Diagnosis is usually clinical supported by dermoscopy. However, in some cases, inflammatory manifestations can be associated with this infection and can mimic other dermatological conditions, making the diagnosis difficult and leading to unnecessary treatments. The objective of this article is to describe the main skin reactions associated with MC infection in order to provide a diagnostic and initial management tool for clinicians dealing with these conditions. Reported manifestations include the BOTE sign, perilesional eczema, Gianotti-Crosti syndrome-like reaction, ID reaction, erythema annulare centrifugum, erythema multiforme, folliculitis, white halo, and atypical manifestations (giant, disseminated, necrotic, polypoidal, and nodular lesions, pseudocysts, abscesses). In pediatric patients with the clinical manifestations described above, infection by molluscum contagiosum pox virus should be considered among the differential diagnoses, and referral to a dermatologist should be made in selected cases.

Paediatric-onset lymphomatoid papulosis: results of a multicentre retrospective cohort study on behalf of the EORTC Cutaneous Lymphoma Tumours Group (CLTG).

BACKGROUND: Lymphomatoid papulosis (LyP) is a rare cutaneous T-cell lymphoproliferative disorder. Comprehensive data on LyP in the paediatric population are scarce. OBJECTIVES: To characterize the epidemiological, clinical, histopathological and prognostic features of paediatric LyP. METHODS: This was a retrospective multicentre international cohort study that included 87 children and adolescents with LyP diagnosed between 1998 and 2022. Patients aged ≤ 18 years at disease onset were included. LyP diagnosis was made in each centre, based on clinicopathological correlation. RESULTS: Eighty-seven patients from 12 centres were included. Mean age at disease onset was 7.0 years (range 3 months-18 years) with a male to female ratio of 2 : 1. Mean time between the onset of the first cutaneous lesions and diagnosis was 1.3 years (range 0-14). Initial misdiagnosis concerned 26% of patients. LyP was most often misdiagnosed as pityriasis lichenoides et varioliformis acuta, insect bites or mollusca contagiosa. Erythematous papules or papulonodules were the most frequent clinical presentation. Pruritus was specifically mentioned in 21% of patients. The main histological subtype was type A in 55% of cases. When analysed, monoclonal T-cell receptor rearrangement was found in 77% of skin biopsies. The overall survival rate was 100%, with follow-up at 5 years available for 33 patients and at 15 years for 8 patients. Associated haematological malignancy (HM) occurred in 10% of cases (n = 7/73), including four patients with mycosis fungoides, one with primary cutaneous anaplastic large cell lymphoma (ALCL), one with systemic ALCL and one with acute myeloid leukaemia. If we compared incidence rates of cancer with the world population aged 0-19 years from 2001 to 2010, we estimated a significantly higher risk of associated malignancy in general, occurring before the age of 19 years (incidence rate ratio 87.49, 95% confidence interval 86.01-88.99). CONCLUSIONS: We report epidemiological data from a large international cohort of children and adolescents with LyP. Overall, the disease prognosis is good, with excellent survival rates for all patients. Owing to an increased risk of associated HM, long-term follow-up should be recommended for patients with LyP.

Lymphomatoid papulosis is a very rare skin condition caused by an abnormal increase in white blood cells (called 'lymphocytes') in the skin. The condition rarely affects children, so most of the scientific data published about this disease focuses on adults. This study involved 12 academic dermatology centres in Europe, the Middle East and North America, and gathered data from about 87 children who presented with symptoms of lymphomatoid papulosis before the age of 19 years. The aim of this study was to better describe this disease in the paediatric population and discuss its treatment options and evolution. We found that the presentation of the disease in children is roughly the same as in adults. Safe and effective treatment options exist. The disease is not life threatening, but it requires investigation by a dermatologist, both to make a careful diagnosis and to monitor it as sometimes associated cancers that originate from blood cells can occur, mostly on the skin.

Does Molluscum Contagiosum Need to be Managed Differently in Atopic Children?

The association between molluscum contagiosum and concomitant atopic dermatitis and its impact on clinical features and treatment outcomes remains unclear. This retrospective study, conducted in the paediatric dermatology clinic of a tertiary medical centre, aimed to compare molluscum patients with and without atopic dermatitis. A total of 615 children with molluscum were included, 13.17% of whom had atopic dermatitis. While the latter group exhibited higher lesion count and itchiness (p=0.026 and p=0.044, respectively), no significant differences were observed in average lesion diameter, ulceration, purulence, and erythema (p=0.239, p=0.730, p=0.682, and p=0.296, respectively). Both groups showed comparable responses to molluscum-specific and supportive treatments, with no distinct difference in outcomes or recurrence of visits. It was concluded that atopic dermatitis does not exacerbate molluscum morbidity, inflammation markers, treatment outcomes or recurrence rates.

Poxvirus infections in dermatology - the neglected, the notable, and the notorious.

The family Poxviridae currently comprises 22 genera that infect vertebrates. Of these, members of the Ortho-, Para-, Mollusci- and Yatapoxvirus genera have been associated with human diseases of high clinical relevance in dermatology. Historically, smallpox had been a notorious health threat until it was declared eradicated by the World Health Organization in 1979. Today, dermatologists are confronted with a variety of poxviral infections, such as farmyard pox, which occurs as a zoonotic infection after contact with animals. In the tropics, tanapox or vaccinia may be in the differential diagnosis as neglected tropical dermatoses. Molluscum contagiosum virus infection accounts for significant disease burden worldwide and is classified as a sexually transmitted infection in certain scenarios. Recently, mpox (monkeypox) has emerged as a public health emergency of international concern, requiring rapid recognition and appropriate management by dermatologists and infectious disease specialists. Advances and new insights into the epidemiology, diagnosis, clinical manifestations and complications, treatment, and prevention of poxviral infections require a high level of expertise and interdisciplinary skills from healthcare professionals linking virology, infectious diseases, and dermatology. This CME article provides a systematic overview and update to assist the practicing dermatologist in the identification, differential diagnosis, and management of poxviral infections.

Molluscum contagiosum survey - common approach and attitude towards treatment and research in Dutch general practice.

BACKGROUND: Molluscum contagiosum (MC) can cause significant burden in children. So far, pharmacological treatment has not been proven beneficial. More rigorous interventions have not been well studied. Current guidelines advise a "wait and see" policy. However, children and their parents frequently visit their GP requesting intervention. Therefore, the aim of this study was to gain insight into the approach to MC by GPs and parents' expectations and to investigate willingness to participate in an interventional study. METHODS: A survey study was carried out among GPs and parents using a questionnaire for each group inquiring about MC and potential study participation. Descriptive statistics were used to analyze results and logistical regression to investigate factors influencing participation. RESULTS: The majority of GPs (88%) preferred an expectative approach; only 21% were willing to participate in a trial as proposed. GPs estimating ≥ 50% of parents would request treatment, were more likely to participate. Most responding parents did or would visit their GP requesting treatment. In contrast to GPs, 58% were willing to participate. Parents preferring cryotherapy or curettage were more likely to participate. CONCLUSION: Our study demonstrated that the majority of GPs preferred a conservative approach, adhering to current guidelines. However, most parents preferred treatment to resolve MC and symptoms. Parents' willingness to participate was much higher than GP's, reflecting parents' desire for treatment. These findings underscore the need for continued therapeutic research. Careful preparation and selection of GPs and patients will be essential to ensure the feasibility of such an endeavor. TRIAL REGISTRATION: This survey study was not part of a clinical trial.

Molluscum contagiosum presenting as periorbital abscess in immunocompetent children.

Molluscum contagiosum presenting as a periorbital region abscess is unusual. The virus generally causes a self-limiting localized disease in children. Presentation as an abscess has been reported mainly in immunocompromised patients. We performed a retrospective study of ten children treated for Molluscum contagiosum infection presenting as periorbital abscess. Data investigated included age, immunocompetence, systemic antibiotic treatment, clinical findings, and histopathology. All children were immunocompetent. Bacterial cultures taken in six of the ten children were positive in two. Seven patients received oral antibiotics before presentation but required IV antibiotics on admission. One patient received IV antibiotics only. All antibiotic treatment had very limited effect. Two patients had no antibiotic treatment. CT imaging in one case where orbital cellulitis was suspected showed no significant intraorbital findings with anterior involvement only. Nine out of ten children had surgery and intra-operative cryotherapy at our center with immediate improvement and recovery. One child whose parents initially refused surgical excision had initial limited clinical improvement of periorbital swelling with antibiotics. However, the lesions were excised shortly following discharge from our hospital at another medical center with a complete cure. Molluscum is a cause of periorbital abscess in immunocompetent children which should be part of the differential diagnosis in periorbital/adnexal infection. Antibiotic treatment has a limited effect, and the abscess is most likely a virally triggered reaction. Surgical excision and intra-operative cryotherapy are curative of the disease in our experience.

[Differential diagnoses of benign eyelid tumors in children and adolescents]. / Differenzialdiagnosen benigner Lidtumoren bei Kindern und Jugendlichen.

BACKGROUND: The clinical diagnosis as well as the treatment approach of periocular tumors in childhood and adolescence can be challenging. Knowledge of the most important differential diagnoses and their clinicopathological correlation is helpful for the treatment approach. OBJECTIVE: The clinical and histological characteristics of various eyelid tumors in childhood and adolescence are presented taking the excision frequencies into consideration. MATERIAL AND METHODS: The frequencies and clinicopathologic correlation of the most important eyelid tumors (n = 485) are presented based on the data of the ophthalmopathology laboratory of the University Eye Hospital Bonn from 1998-2023. RESULTS: The most frequent tumor in childhood and adolescence is chalazion (57.3%), followed by dermoid cysts (16.7%) and molluscum contagiosum (9.6%). Other lesions of childhood and adolescence include pilomatrixoma (2.1%), hemangioma and other vascular malformations (4.7%) and rare differential diagnoses, such as subcutaneous calcifying nodules and xanthogranuloma. Guidance on the approach in different age groups is presented in the form of a decision tree. CONCLUSION: Tumors in children and adolescents are mostly benign, yet there are important indications for excision. A histological examination of any excised tissue in childhood and adolescence is obligatory because unexpected findings are not uncommon and the spectrum of lesions also differs from that in adulthood. Knowledge of the histological picture can be very helpful in the preoperative clinical classification and for planning further procedures.

Pharmacokinetic Profile, Safety, and Tolerability of Topical Berdazimer Gel, 10.3% in Patients With Molluscum Contagiosum.

BACKGROUND: Berdazimer (SB206), gel 10.3% is a novel, topical, nitric oxide–releasing agent intended for molluscum contagiosum (MC) treatment. METHODS: A 12-week, open-label, multicenter trial evaluated the safety, tolerability, and pharmacokinetic (PK) parameters of berdazimer gel, 10.3% applied topically once daily for the treatment of MC. Patients were aged ≥6 months with >20 molluscum lesions. The primary endpoint was the PK profile of the hydrolyzed N-methylaminopropyl-trimethoxysilane (hMAP3) monomer and nitrate during a 2-week period of once-daily berdazimer gel, 10.3% application (PK period) under maximal use conditions. Safety and tolerability were evaluated throughout the 12-week study period. RESULTS: Half of the 34 enrolled patients (17) were female and most (97.1% [33/34]) were white. Patients were 2 to 12 years old (mean, 5.3 years) with a mean of 50 MC lesions at baseline (mean time since MC awareness, 12.4 months). No patients had quantifiable plasma hMAP3 concentrations on day 1. On day 15, 2 patients had quantifiable plasma hMAP3 concentrations; however, the maximum concentration (33.9 ng/mL) was >10-fold lower than the no observed adverse effect level (NOAEL) in an animal toxicology study. Mean nitrate concentration–time profiles were similar on days 1 and 15 and remained flat for all patients throughout the 2-week PK period. The highest plasma methemoglobin level observed was 3.2%. Application-site pain (13/34 [38.2%]) and application-site erythema (6/34 [17.6%]) were the most frequent treatment-emergent adverse events (TEAEs), and most TEAEs were mild or moderate. CONCLUSIONS: Once-daily berdazimer gel, 10.3% was well-tolerated with minimal systemic absorption. J Drugs Dermatol. 2022;21(10):1104-1110. doi:10.36849/JDD.6938.