Squaric acid immunotherapy for warts in children

Efficacy of Intralesional Measles Mumps Rubella Vaccine in the Treatment of Verruca Vulgaris: An Interventional Study

Background A wart is a mucocutaneous illness caused by the growth of HPV-infected skin or mucosal cells. Intralesional immunotherapy makes use of the immune system's ability to identify injected antigens, which might cause a delayed-type hypersensitivity reaction not just to the antigen but also to the wart virus. This, in turn, improves the immune system's ability to identify and eliminate HPV not just at the treated wart but also at distant places, as well as prevent recurrences. Aims and objectives To study the efficacy of the intralesional measles, mumps, and rubella (MMR) vaccine in verruca vulgaris and its side effects. Materials and methods Interventional research with a 94-case sample size was conducted over a period of seven months. A volume of 0.3 ml of the MMR vaccination was reconstituted with sterile water and injected into the largest wart at three-week intervals until complete clearance or for a maximum of three treatments. Following a six-month observation period, patients were evaluated to look for recurrence, and the degree of response was categorized as total, partial, or none at all. Results The youngest case included in the study was of age 10 years and the eldest case was of 45 years. The mean age was 28.22± 10.98. Of 94 patients, 83 (88.3%) were men and 11 (11.7%) were women. Complete remission was reported in 38 (40.42%) cases, a partial response in 46 (48.94%) cases, and no response in 10 (10.63%) cases. All 38 patients who showed complete clearance had a duration of warts in six months or less. The pain was a universal complaint (100%) after each visit followed by bleeding at 25.53%. Flu-like symptoms were noted in three cases after the first dose and two cases after the second dose, while urticaria was seen in one case during all visits. Cervical lymphadenopathy was observed in two cases after the first dose. Erythema multiforme minor was seen only in one patient after the first dose. Conclusion Intra-lesional MMR vaccine therapy proved to be a simple and safe treatment option in cases having multiple warts. The response rate may increase if a higher concentration of vaccine (0.5ml) and additional doses (maximum of five doses) are given.

Use of Contact Immunotherapy in the Treatment of Skin Diseases Other than Alopecia Areata

For decades, contact immunotherapy with dinitrochlorobenzene, diphencyprone, and squaric acid dibutylester has played an important role in both clinical practice and scientific research. It is listed as the first-line treatment for extensive alopecia areata and was more recently approved for melanoma treatment as an orphan drug in the USA. Moreover, owing to the relative low cost and safety, topical immunotherapy has also been used in many infectious, neoplastic, and inflammatory dermatological diseases. It is especially valuable in vulnerable groups, for cosmetic/pain sensitive areas, or for multiple lesions. In this review, we summarize the current evidence supporting the use of contact immunotherapy for treatment of skin diseases, from articles collected from PubMed database. Owing to space limitation and already numerous studies focusing on alopecia areata, we include only skin diseases other than alopecia areata. In addition to diseases that have been reported to be treated by contact immunotherapy, the hypothesized mechanism, prognosis prediction, efficacy, and safety of these topical agents are discussed.

Topical therapy for regression and melanoma prevention of congenital giant nevi

Giant congenital melanocytic nevi are NRAS-driven proliferations that may cover up to 80% of the body surface. Their most dangerous consequence is progression to melanoma. This risk often triggers preemptive extensive surgical excisions in childhood, producing severe lifelong challenges. We have presented preclinical models, including multiple genetically engineered mice and xenografted human lesions, which enabled testing locally applied pharmacologic agents to avoid surgery. The murine models permitted the identification of proliferative versus senescent nevus phases and treatments targeting both. These nevi recapitulated the histologic and molecular features of human giant congenital nevi, including the risk of melanoma transformation. Cutaneously delivered MEK, PI3K, and c-KIT inhibitors or proinflammatory squaric acid dibutylester (SADBE) achieved major regressions. SADBE triggered innate immunity that ablated detectable nevocytes, fully prevented melanoma, and regressed human giant nevus xenografts. These findings reveal nevus mechanistic vulnerabilities and suggest opportunities for topical interventions that may alter the therapeutic options for children with congenital giant nevi.

Autoimplantation – An Immunological Treatment For Multiple Warts

Introduction. Warts are benign epithelial lesions that involve skin and mucosa. Successful management depends on the patient’s immunity, site and type of wart. In spite of huge therapeutic armory available, no treatment has been found to be effective so far.

Objective. To evaluate the effectiveness of autoimplantation in the management of multiple warts.

Material and Methods. This is a hospital based prospective study of forty patients with multiple warts. A prospective, hospital-based study included forty cases of multiple warts for autoimplantation. Resolution of warts within three months was taken as complete clearance; the follow up of any recurrence lasted six months.

Results. The majority of patients were males (69.7%), belonging to 21–30 years age group (57.6%). Complete resolution was observed in 25 patients, partial response was achieved in 5 patients and there was no response in 3 patients. The majority of patients did not have any complication or recurrence

Conclusion. Autoimplantation is a simple, daycare, effective procedure. It provides resistance by inducing cell mediated immunity and also prevents recurrence to a great extent.

Successful Treatment of Multiple Common Warts With Intralesional Ozone

BACKGROUND

Although there are multiple treatments for warts, wart management remains a challenge. Ozone therapy is an emerging treatment for infectious and noninfectious dermatological diseases.

OBJECTIVE

To assess intralesional ozone gas safety and efficacy in multiple warts management.

MATERIALS AND METHODS

Seventy-four adult patients with multiple common warts were included in this study. They were randomly assigned into 2 groups: first group comprised 44 patients treated with intralesional ozone gas, and the second group comprised 30 patients who received intralesional saline injection. In both groups, warts in all patients were directly injected weekly until complete clearance occurred or for a maximum of 10 treatment sessions. The subjects were followed for 6 months to record any recurrences.

RESULTS

In the ozone group, 25 patients (56.8%) had a complete response with an excellent cosmetic outcome, 15 patients (34.1%) showed a partial response, and 4 patients (9.1%) had no response. More subjects responded to ozone than to saline (p < .001). Ozone therapy was associated with mild side effects, including pain at time of injection, numbness, and fatigue.

CONCLUSION

Intralesional ozone is effective and safe for the treatment of multiple warts.

Treatment of cutaneous viral warts in children: A review

Viral warts or verruca are very common skin infections in children. Although benign, lesions can be extensive, painful, bleed, or lead to cosmetic disfigurement. Although spontaneous resolution can occur, parents often bring their children for treatment, especially when they are symptomatic. Many publications have assessed the efficacy and safety of treatment of warts in adults. However, treatment in children can be challenging due to their immune responses and lower threshold for pain. We review the current literature on the methods, efficacy, and side effect profile of common treatment modalities for cutaneous viral warts in children. There is evidence that salicylic acid and cryotherapy are effective, and although cryotherapy is more effective, there is a higher risk of side effects such as pain and blistering. Combination treatment with salicylic acid and cryotherapy may reduce these side effects. Although there is limited data, other treatment options such as cantharidin, immunotherapy and other mechanical therapies, for example, carbon dioxide lasers, may also be considered, especially for recalcitrant lesions.

The efficacy of diphencyprone immunotherapy for the treatment of cutaneous warts: a systematic review and meta-analysis

BACKGROUND

Cutaneous warts, a common skin condition, may resolve spontaneously or become recalcitrant. Diphencyprone has been shown by many studies to have efficacy in treating warts, with varied results.

OBJECTIVES

We aimed to perform a meta-analysis of the cure rate following the use of diphencyprone immunotherapy as a cutaneous wart treatment.

MATERIALS AND METHODS

The databases of Medline, PubMed, Embase, ClinicalTrials.gov, and Cochrane Controlled Trials Register were searched for prospective and retrospective cohort studies and randomized controlled trials reporting a cure rate for diphencyprone immunotherapy between 1984 and 2018. The Comprehensive Meta-Analysis software (Biostat Inc) was used to perform a meta-analysis of the diphencyprone pool efficacy.

RESULTS

A total of 153 studies were obtained by searching the databases. After screening for eligibility, 14 studies were included (6 prospective studies, 4 retrospective studies, 3 randomized controlled trials, and 1 case report), representing a total of 851 patients. The random-effects pooled efficacy for diphencyprone was 75.5% (95% CI, 64.6%-83.9%; I² = 87%).

CONCLUSIONS

Diphencyprone immunotherapy has a high efficacy to cure warts. This method may be used as an adjunctive modality for the treatment of warts in cases of conventional treatment failure.

Immune characteristics correlating with HSV-1 immune control and effect of squaric acid dibutyl ester on immune characteristics of subjects with frequent herpes labialis episodes

Introduction

Differences in immune characteristics, including immune gene expression by peripheral blood mononuclear cells (PBMCs), correlating with herpes labialis and good or poor immune control of herpes simplex virus type 1 (HSV‐1), and how these characteristics change after dosing with squaric acid dibutyl ester (SADBE), were investigated.

Methods

PBMCs were collected from persons positive for IgG against HSV‐1 and having frequent, infrequent, or no herpes labialis outbreaks. The PBMCs were tested for proliferation against HSV‐1 and a fungal antigen (Candida) and immune gene expression in the presence of HSV‐1 and Candida. On day 1 after blood collection the subjects with frequent outbreaks were dosed topically on the arm once with SADBE, and their PBMCs were collected and tested 8 weeks later.

Results

Those with good immune control of their HSV‐1 infection (fewer outbreaks) differ from those with poorer immune control in these ways: (1) Greater PBMC proliferation in vitro to HSV‐1, HSV‐1‐infected cell extracts, and Candida considered together (P < 0.01). (2) Higher expression of IFNG and five other immune‐related genes (P < 0.05 for each) and lower expression of IL5 and two other immune‐related genes (P < 0.05 for each) in PBMCs in vitro stimulated with HSV‐1 virus. The subjects with frequent outbreaks were treated once with SADBE, and 56 days later the PBMCs of these subjects differed from PBMCs from the same subjects taken on day 1 before treatment in exactly the same ways listed above as differences between those with good and poor immune control of HSV‐1, and at the same levels of significance.

Conclusions

Higher IFNG and lower IL5 expression by PBMCs in the presence of HSV‐1 correlate with fewer herpes labialis outbreaks, and a single topical dose of SADBE to the arm of subjects with frequent herpes labialis episodes improves immune response to HSV‐1.

Electrostatic potentials and average electron densities of bioisosteres in methylsquarate and acetic acid

Background: The bioisosterism in −CO2H and −C4HO3 is exploited using the quantum theory of atoms in molecules and molecular electrostatic potentials (ESP). Results & discussion: Bioisosteres in methylsquarate and acetic acid, in the neutral/anionic forms, have average electron densities that differ by less than 2% (i.e., ∼0.01 atomic units) while irrespective of the capping group. The topography of the ESP reveals similarities in the case of the neutral species but not in the anionic forms. Conclusion: The nonclassical bioisosteres in methylsquarate and acetic acid have average electron densities that are similar and relatively insensitive to the ionization state (neutral or anionic) or its studied capping group (H, CH3, Cl or phenyl). The ESP reveals similarities in the topography of neutral molecules.

Psychophysical measurements of itch and nociceptive sensations in an experimental model of allergic contact dermatitis

Allergic contact dermatitis (ACD) is a common condition that can significantly affect the quality of life. Contact with allergens results in delayed hypersensitivity reactions involving T lymphocytes, with associated skin inflammation and spontaneous itch and nociceptive sensations. However, psychophysical studies of these sensations are lacking. In the present study, we sensitized 8 healthy volunteers to squaric acid dibutyl ester (SADBE). Two weeks later, 1 volar forearm was challenged with SADBE, and the other with acetone vehicle control. Subsequently, participants rated the maximal perceived intensity of spontaneous itch, pricking/stinging, and burning every 6 to 12 hours for 1 week, using the generalized Labeled Magnitude Scale. In the laboratory, they judged stimulus-evoked sensations within and outside the chemically treated area. The SADBE- but not the acetone-treated skin resulted in 1) localized inflammation, with spontaneous itch and nociceptive sensations peaking at 24 to 48 hours after challenge, 2) alloknesis, hyperknesis, and hyperalgesia to mechanical stimuli that were reduced or eliminated by anesthetic cooling of the SADBE-treated area and restored on rewarming, suggesting that sensations and dysesthesias are dependent on ongoing peripheral neural activity, and 3) enhanced itch to intradermal injection of histamine, BAM8-22, or β-alanine. This experimental model of T-cell-mediated inflammation may prove useful in evaluating potential treatments of itch from ACD.

PERSPECTIVE

In a model of allergic contact dermatitis, experimentally applied in humans, psychophysical measurements were obtained of persistent, spontaneous itch and enhanced stimulus-evoked itch and pain sensations. These sensory measurements will be useful in the identification of the neural mechanisms underlying inflammatory itch and pain.

Examining the efficacy and safety of squaric acid therapy for treatment of recalcitrant warts in children

The objective of the study was to determine the safety and efficacy of squaric acid dibutyl ester (SADBE) therapy on the treatment of recalcitrant warts in children. This retrospective chart review examined 72 patients treated using SADBE from July 2002 to December 2012. Patients were followed for 6 months to 11 years. Patients were treated at a pediatric dermatology outpatient clinic at the University of North Carolina at Chapel Hill. Seventy-two children with verrucae who failed initial treatment for warts were selected for the study. Full long-term follow-up was obtained in 48 patients. Four patients discontinued the use of SADBE because of adverse effects. The primary study outcome was efficacy of SADBE treatment. Adverse effects, dosages administered, type of wart, other cutaneous disease present, and level of immunosuppression were measured. Forty of 48 (83%) patients in whom treatment outcomes could be obtained reported complete resolution of their warts. Seventy percent of patients used a maximum concentration of 0.4% SADBE and 60% of patients reported no adverse effects. The majority of patients treated with SADBE reported complete resolution of warts. Most patients reported no adverse effects even while receiving doses as high as 2% daily. This study shows that SADBE is a safe and effective treatment for recalcitrant warts in children.

Hydrogen-bond landscapes, geometry and energetics of squaric acid and its mono- and dianions: a Cambridge Structural Database, IsoStar and computational study

As part of a programme of work to extend central-group coverage in the Cambridge Crystallographic Data Centre's (CCDC) IsoStar knowledge base of intermolecular interactions, we have studied the hydrogen-bonding abilities of squaric acid (H2SQ) and its mono- and dianions (HSQ(-) and SQ(2-)) using the Cambridge Structural Database (CSD) along with dispersion-corrected density functional theory (DFT-D) calculations for a range of hydrogen-bonded dimers. The -OH and -C=O groups of H2SQ, HSQ(-) and SQ(2-) are potent donors and acceptors, as indicated by their hydrogen-bond geometries in available crystal structures in the CSD, and by the attractive energies calculated for their dimers with acetone and methanol, which were used as model acceptors and donors. The two anions have sufficient examples in the CSD for their addition as new central groups in IsoStar. It is also shown that charge- and resonance-assisted hydrogen bonds involving H2SQ and HSQ(-) are similar in strength to those made by carboxylate COO(-) acceptors, while hydrogen bonds made by the dianion SQ(2-) are somewhat stronger. The study reinforces the value of squaric acid and its anions as cocrystal formers and their actual and potential importance as isosteric replacements for carboxylic acid and carboxylate functions.

Immunotherapy with intralesional Candida albicans antigen in resistant or recurrent warts: a study

BACKGROUND

Warts are sometimes resistant or they tend to recur after every possible destructive therapy. Immunotherapy with skin-test antigens has been used as a viable therapeutic option in such recalcitrant cases.

AIM

The aim of the study was to evaluate the response of resistant or recurrent warts to intralesional Candida albicans antigen immunotherapy.

MATERIALS AND METHODS

A total of 40 patients with resistant or recurrent warts who showed a positive test reaction to C. albicans antigen were given intralesional injections of purified C. albicans antigen solution in a single wart at 3-weekly intervals for a total of three doses. The patients were monitored for resolution of the injected wart as well as other untreated warts. The patients who responded positively were then followed up for any relapses over the next 6 months. Adverse events, if any, were also documented.

RESULTS

Of the 40 patients enrolled in the study, 34 completed the total treatment protocol of three injections and 6 months of follow-up. In these 34 patients, 19 (56%) showed a complete resolution of warts at all places on the body. In addition, two patients (6%) showed a partial or complete resolution of the treated wart, but there was no effect on the untreated warts. Thirteenpatients (38%) failed to show any response to the treatment regimen. In all patients showing resolution of all the warts, there were no relapses at any site over the next 6 months of follow-up. The most common adverse effect seen was pain during the intralesional injection.

CONCLUSIONS

Intralesional Candida immunotherapy seems to be an effective treatment option in more than half of the patients who fail to show a positive response to destructive modes of treatment or in whom there are multiple recurrences.

LIMITATIONS

The small sample size and lack of control group are the main limitations of the study.

Intralesional antigen immunotherapy for the treatment of warts: current concepts and future prospects

Many destructive and immunotherapeutic modalities have been used for the management of warts; however, an optimal treatment with high efficacy and absent or low recurrence has not been explored to date. Recently, the use of intralesional immunotherapy with different antigens has shown promising efficacy in the treatment of warts. We review the different aspects of this new modality, including candidates, types of warts treated, dosage, number and interval between treatment sessions, mode of action, efficacy, adverse effects, recurrence rate, advantages, disadvantages, current place and future prospects. A literature review revealed that healthy immune subjects are the best candidates, and a pre-sensitization test is usually done before the start of therapy. The dosage, the number and interval between sessions, and the success rates varied among the different studies. The mode of action is still uncertain, but is essentially mediated through stimulation of T helper-1 cell cytokine response. Adverse effects are mild and generally insignificant, and the recurrence rate is absent or low. Intralesional antigen immunotherapy seems to be a promising, effective and safe treatment modality for viral warts. Future well-designed and controlled studies would help to more clearly define its place in the challenging field of wart therapy.

Treatment of common warts with the immune stimulant Propionium bacterium parvum

BACKGROUND: Warts are epithelial proliferations in the skin and mucous membrane caused by various types of HPV. They can decrease spontaneously or increase in size and number according to the patient's immune status. The Propionium bacterium parvum is a strong immune stimulant and immune modulator and has important effects in the immune system and it is able to produce antibodies in the skin. OBJECTIVE: To show the efficacy of the Propionium bacterium parvum in saline solution in the treatment of skin warts. METHODS: A randomized double-blind study. Twenty patients with multiple warts were divided into two groups: one received 0,1ml intradermal injection of placebo solution in just one of the warts and the other received 0,1 ml of saline solution of Propionium bacterium parvum, one dose a month, for 3 to 5 months. RESULTS: Among the 20 patients who participated in the study, ten received the placebo and ten received the saline solution with Propionium bacterium parvum. In 9 patients treated with the Propionium bacterium parvum solution the warts disappeared without scars and in 1 patient it decreased in size. In 9 patients who received the placebo no change to the warts was observed and in 1 it decreased in size. CONCLUSIONS: The immune modulator and immune stimulant Propionium bacterium parvum produced antibodies in the skin which destroyed the warts without scars, with statistically significant results (P<0,001), and cured 90 % of the patients. We suggest the use of the immune stimulant in the treatment of warts.

Treatment of cutaneous warts: an evidence-based review

Cutaneous warts are common skin lesions caused by human papillomavirus infection. Treatment is aimed at relieving the patient's physical and psychological discomfort and at preventing the spread of infection by autoinoculation. Among the available medical and destructive therapeutic options for cutaneous warts, none is uniformly effective or virucidal. Moreover, in most cases their safety and efficacy has not been assessed in double-blind, controlled clinical trials, so that the reproducibility of many of the listed treatments is difficult to evaluate and a possible placebo effect cannot be ruled out. The aim of this article is to describe the outcome of current therapies for each clinical wart type according to evidence-based medicine studies published in the literature. For each clinical form, the existing treatments are classified as first-, second-, and third-line therapy. First-line therapy includes medical treatments (salicylic acid, silver nitrate, glutaraldehyde) that are useful to treat a single wart or a few and/or small common warts of short duration (less than 1 year). If these treatments have failed or are contraindicated, cryotherapy may be considered as second-line therapy. For recurrent or difficult-to-treat lesions, third-line therapy includes a variety of alternative therapeutic options (topical, intralesional, systemic, and physical destruction) that are generally off-label (not US FDA approved), and whose use is limited by drawbacks or adverse effects. From pooled evidence-based medicine data, it is possible to conclude that significantly higher remission rates may be expected only with cryotherapy and salicylic acid used in combination.

Comparative study on the sustained efficacy of diphencyprone immunotherapy versus cryotherapy in viral warts

This study compared the sustained clearance rate of viral warts treated with topical diphencyprone (DCP) therapy (group A) versus cryotherapy (group B). After 12 months follow-up, 93.3% (42/45) of group A and 76.3% (29/38) of group B presented sustained clinical clearance. Our data suggest that topical DCP therapy may lead to the induction of the long-term immunity to human papillomavirus (HPV).

Successful treatment of recalcitrant warts with topical squaric acid in immunosuppressed child

Although spontaneous resolution of verrucous vulgaris is the norm, many treatment modalities are available including local destruction, chemotherapy, immunotherapy, and sensitizing agents. The choice of treatment will vary with patient's age and desire for treatment, prior treatments, potential side effects, location of lesions, and patient's immune status. Treatment of verruca vulgaris in immunosuppressed patients presents therapeutic challenges as lesions in this population are often refractory to conventional modalities. Here we present a case of successful treatment of recalcitrant warts with topical squaric acid in an immunosuppressed child.

Topical immunomodulation: modes of action with clinical correlation

Many classes and preparations of immunomodulators are available to the clinician, serving as stimulatory or inhibitory influences on a variety of disease states. To maximize their efficacy, it is important for the clinician to take a step back from the usual routine of treating symptoms and consider the immune processes that took place to create inflammation, tumors, or responses to infections. From there, after considering the short-term and long-term consequences of the treatment, one can match the immune profile of the disease to the treatment. Most importantly, immunomodulators provide the opportunity to do what is best for the patient at that time, as well as for control of the future of the disease, whether it is acute or chronic.

Pulsed dye laser therapy for pediatric warts

Viral wart infections constitute one of the most common pediatric skin diseases, and various modalities have been used to manage them. Although pulsed dye laser therapy is known to be a safe and efficacious modality, the reported cure rates for this method have varied, and no studies have reported treatment of pediatric patients alone. This prospective, nonblinded, nonrandomized study was performed to evaluate the efficacy and safety of pulsed dye laser therapy for pediatric warts. We found that this method is safe, relatively effective, and worth considering as an additional therapeutic option for viral warts in children, although not as a first-line therapy.

How and when to treat molluscum contagiosum and warts in children

Warts and molluscum contagiosum are common skin diseases in children and are usually self-limiting. The decision of whether to treat children with molluscum or warts should be individualized to the patient and his or her family. Considerations include how symptomatic the lesions are, the extent and duration of disease, the ability of the child and the parents to tolerate and comply with treatment recommendations, and any underlying medical conditions (Table, see page 219). Recurrences of molluscum contagiosum and especially warts are common, and realistic expectations regarding the potential for treatment failure and recurrence should be discussed with the child and his or her family prior to initiating any therapy. As pediatric practitioners, we all remain acutely aware of our patients' physical and psychological development and the potential for any intervention to influence this development. Although various treatment modalities now exist for the treatment of these viral diseases, any intervention should be balanced against these considerations.

Topical Immunomodulation in Dermatology: Potential of Toll-like Receptor Agonists

BACKGROUND

Topical immunomodulators include both immunostimulatory and immunosuppressive agents. If successful, topical immunotherapy may represent an important improvement in the therapy of inflammatory dermatoses, viral infections, and cancers of the skin and genital mucosa. Topical immunotherapy using obligate contact sensitizers such as diphencyprone or dinitrochlorobenzene has been used against viral (e.g., common warts) and autoimmune diseases (e.g., alopecia areata).

RESULTS

Newer agents such imidazoquinolines (imiquimod and resiquimod) act by cytokine secretion from monocytes/macrophages (interferon-alpha, interleukin-12, tumor-necrosis factor-alpha). The locally generated immune milieu leads to a Th1-dominance and cell-mediated immunity that have been clinically used to treat viral infections such as human papillomavirus, herpes simplex virus, and mollusca. Although these agents improve antigen presentation by dendritic cells, they also act on B cells leading to the synthesis of antibodies such as IgG2a. We have also introduced this treatment against cancerous lesions including initial squamous cell and basal cell carcinoma in immunocompetent and immunosuppressed patients. We provide examples of successful treatment of squamous cell cancer using topical imiquimod.

CONCLUSION

The available and additional Toll-like receptor agonists will help to improve the specific dermatologic therapy. Topical immunotherapy with both immunostimulatory and immunosuppressive agents bears potential for effective and patient friendly treatment of inflammatory, infectious, and cancerous skin diseases. Long-term evaluation will define the tolerability and safety profile of these novel topical agents.

Human papillomavirus infections in children

PURPOSE OF REVIEW

The human papillomavirus is a ubiquitous 55-nm DNA virus that causes a variety of clinical disease states in children, commonly referred to as warts. The natural history of warts is spontaneous regression through the development of a complex blend of cell-mediated and humoral immunity. Although spontaneous immunity can develop, as many as one third of children will have persistent human papillomavirus infection beyond 2 years. Therapeutic modalities are manifold, primarily because no therapy is universally effective. The purpose of this review is to update the reader with the latest information on the human papillomavirus and its therapeutics in children.

RECENT FINDINGS

Recently, encouraging research has been conducted in human papillomavirus, including destructive and immunologic therapies. Vaccines tailored to genital human papillomavirus strains are just coming into clinical use.

SUMMARY

Manipulation of the immune system through medications or vaccination will likely help contain human papillomavirus in the future and prevent secondary human papillomavirus oncogenesis of the skin and cervix.

Squaric Acid N-Hydroxylamides: Synthesis, Structure, and Properties of Vinylogous Hydroxamic Acid Analogues

The synthesis of squaric acid N-hydroxylamide esters 5 and amides 6 from dimethyl squarate 2a is described. These derivatives are analogues of the naturally occurring iron(III) chelator hydroxamic acid. On the basis of a comparative reactivity study, a concerted retro-Cope mechanism for the formation of the N-hydroxylamide esters 5 by reaction of dimethyl squarate with hydroxylamines is proposed. A preliminary iron(III) binding study of these hydroxamic acid analogues is presented, demonstrating binding of iron(III) to amides 6 in aqueous solutions, while the esters 5 did not show any sign of metal ion binding. 13C NMR spectroscopic data (chemical shift and spin-lattice relaxation time determination) of these and related derivatives delineate the resonance structures predominant in these molecules. The resonance structures of the derivatives rationalize their spectroscopic data, chemical reactivity, and iron(III) binding properties. Single-crystal X-ray structure analyses of squaric acid N-hydroxylamide ester 5b and squaric acid N-hydroxylamide amide 6c confirm their connectivity and provide structural evidence supporting the spectroscopically derived conclusions. The squaric acid N-hydroxylamides are potentially useful in the construction of chemosensors for iron(III).

Immunotherapy for recalcitrant warts in children using intralesional mumps or Candida antigens

Intralesional injection of mumps and Candida skin test antigens has been shown to be effective in the treatment of warts. Warts are generally difficult to treat in children. To determine the efficacy of intralesional skin test antigen injection for the treatment of resistant warts in children, we treated 47 pediatric patients with one or more warts with intralesional injection of mumps or Candida skin test antigen into one wart. Twenty-two patients (47%) with resistant warts experienced complete resolution of treated warts. An average of 3.78 treatments were necessary. An additional 34% of children had a greater than 25% improvement in their warts. Sixty-eight percent of subjects with more than one wart also noted at least partial resolution (greater than 25% resolution) of untreated warts at distant sites, with 34% experiencing complete resolution. We concluded that intralesional injection of skin test antigens is an effective therapy for children who have recalcitrant, nongenital, cutaneous warts.

The therapeutic use of topical contact sensitizers in benign dermatoses

Topical therapy using contact sensitizers has been practised since the 1960s to treat conditions associated with an altered immunological state. Dinitrochlorobenzene, squaric acid dibutyl ester and diphencyprone are most commonly employed in the therapy of alopecia areata and viral warts. Few dermatology departments in the U.K. provide such treatment. This systematic review discusses the various contact sensitizers used for topical immunotherapy, the methodology of treatment, factors influencing efficacy and likely adverse effects.

Cimetidine and levamisole versus cimetidine alone for recalcitrant warts in children

Various immunomodulating agents have been used in the treatment of recalcitrant warts, but none is uniformly effective. Aggressive surgical therapy of warts in children is painful and may require general anesthesia. Drugs such as cimetidine and levamisole have been tried with varying success rates. Given the different target of activities of immunomodulation by cimetidine and levamisole, we questioned whether the combination might be more effective and conducted a double-blind comparative trial of a combination of cimetidine and levamisole versus cimetidine alone. Forty-four patients with multiple recalcitrant warts were assigned to one of two treatment groups (groups A and B) in double-blind fashion. Of the 44 patients, 19 in group A and 20 in group B could be evaluated. At the end of therapy, cure rates (complete clearance) obtained were 31.5% of those in group A and 65% of those in group B (combination treatment). A statistically significant improvement was seen in patients treated with the combination of levamisole and cimetidine (p=0.0150). The rate of regression was faster in group B (average regression period of 7.8 weeks compared with 11 weeks in group A). The present study demonstrated that the combination of cimetidine with levamisole is more effective than cimetidine alone and is a highly effective therapy for the treatment of recalcitrant warts.