Morphological and Clinical Patterns of Paederus Dermatitis.

Background The objective of the present study was to describe the morphological and clinical patterns of paederus dermatitis (PD). Methodology This retrospective case series was conducted in the outpatient department of the Department of Dermatology, Srinivasan Medical College and Hospital, Trichy, Tamil Nadu, between June 2023 and August 2023 among patients with a clinical diagnosis of PD. Results This study included a total of 10 patients. The mean (SD) age of the patients was 19.4 (1.9) years. More than half of the patients (60.0%) were males. Of the 10 patients included, four (40.0%) were from rural areas, three (30.0%) were from urban areas, and three (30.0%) were from semi-urban areas. The maximum number of cases was reported between June and September. The most common presenting complaint was a burning sensation in 80.0% of the patients, followed by pain in 80.0% and blisters in 20.0% of the patients. The mean (SD) duration of the lesion was 4.2 (1.3) days. Regarding the clinical pattern of lesions, linear lesions were the most common (40.0%), followed by erythematous lesions with central gray area in 30.0%, kissing lesions in 20.0%, and burnt appearance in 10.0% of the lesions. Nearly half of the patients presented with lesions in the face (40.0%), the most common site in the present study, followed by lesions in the leg (20.0%), and lesions in the axilla, chest, arm, and back (10.0% each). Conclusions Understanding the epidemiology and clinical manifestations of this condition is crucial for accurate diagnosis, timely management, and public health interventions aimed at preventing Paederus beetle-related dermatitis.

A Case Series of Paederus Dermatitis: Understanding Its Varied and Diverse Clinical Presentations.

Introduction  Paederus dermatitis arises from inadvertent skin contact with insects of the genus Paederus, leading to irritant contact dermatitis. This study aims to highlight the diverse clinical presentations and the remarkable ability of the disease to mimic various dermatological conditions.  Methodology  A total of 15 patients diagnosed with Paederus dermatitis in a period of four months from August 2023 to November 2023 were included in this retrospective study. The demographic profile, detailed history, clinical presentation, and site of lesion distribution were documented.  Results  Out of 15 patients, nine were males, and eight were females. All patients exhibited a sudden onset of lesions accompanied by burning and pain, with an average duration of approximately 2.5 days. The most prevalent clinical presentation was the linear type, followed by kissing lesions, an erythematous patch with a central gray area, Nairobi eye, burnt appearance, and post-inflammatory pigmentation.  Conclusion  Paederus dermatitis is common in tropical areas like India but is prone to misdiagnosis due to its varied presentation. Increased awareness can lead to accurate diagnoses and simpler treatment plans, reducing patient confusion.

The pederin-producing bacteria density dynamics in Paederus fuscipes at different developmental stages.

Pederin, a defensive toxin in Paederus fuscipes, is produced by an uncultured Gram-negative symbiont, which establishes a stable symbiotic relationship with a female host before completion of metamorphosis. However, the transmission process of pederin-producing bacteria (PPB) in P. fuscipes at different life stages remains unknown. Herein, the PPB population dynamics and transcriptome atlas for P. fuscipes development (egg, first-instar larva, second-instar larva, pupa, and newly emerged female and male) were characterised. We found that a microbial layer containing PPB covered the eggshell, which could be sterilised by smearing the eggshell with streptomycin. Maternal secretions over the eggshell are likely the main PPB acquisition route for P. fuscipes offspring. The PPB density in eggs was significantly higher than that in other life stages (p < 0.05), which demonstrated that the beetle mothers gave more PPB than the larvae acquired. Physiological changes (hatching and eclosion) led to a decreased PPB density in P. fuscipes. Pattern recognition receptors related to Gram-negative bacteria recognition were identified from P. fuscipes transcriptomes across various life stages, which might be used to screen genes involved in PPB regulation. These results will help advance future efforts to determine the molecular mechanisms of PPB colonisation of P. fuscipes.

Clinico-dermatologic patterns of Paederus dermatitis in a teaching hospital, South India.

Background: Paederus dermatitis (PD) is common skin condition occurring in South India caused due to contact with Rove beetle. It is often misdiagnosed due to wide difference in its presentation. The aim of this study was to describe the clinical, sociodemographic, and environmental condition of patient's presenting with PD. Methodology: A descriptive study was done among all patients diagnosed of PD at the Dermatology department of a teaching hospital in Trichy, South India, between January and December 2020. A detailed clinical history, examination of the lesion, and systemic examination was done. Patients were followed-up after 1 week to re-assess the lesion. A total of 117 cases were included in the final analysis. Results: The mean age of patients was 24.54 ± 11.8 years. Female were 51% with 84.6% residing in rural area. Majority of the cases presented between January and May. Presence of thick vegetation (85.5%) and sleeping with windows open (60.7%) were found to be the common risk factors. Most patients reported noticing the lesion in the morning with sudden onset associated with redness and tenderness with a bizarre pattern of lesion. Face, neck, and upper extremity were the most affected sites with burning sensation and itching, experienced by 82.1% and 76.1%, respectively. Ocular involvement with peri-orbital odema was seen among 17% of cases. Post-inflammatory pigmentation was present in 92.1% patients. Conclusion: PD present has a varying degree of skin lesions with absence of the typical linear pattern. Knowledge of its presentation is important to avoid misdiagnosis.

Clinical manifestations and progression, seasonal variation, and environmental factors associated with Paederus dermatitis among patients attending the outpatient dermatology clinic of Thailand's largest national tertiary referral center: a prospective cohort study.

INTRODUCTION: Paederus dermatitis (PD) is a skin reaction to a chemical substance called paederin, which emanates from a beetle of Paederus spp. This study's objective was to investigate the clinical manifestations and progression, seasonal variation, and environmental factors associated with PD among patients attending the outpatient dermatology clinic of Siriraj Hospital. METHODS: This prospective cohort study included patients who were diagnosed with PD at the Department of Dermatology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand during the October 2017 to July 2018 study period. Sociodemographic and environmental data were collected by questionnaire. RESULTS: Twenty-five PD patients (16 females, 9 males) were included with a mean age of 40.9 years (range 17-69 years). The most common sites were the upper and lower extremities. Erythema, linear, and kissing lesions (where two skin surfaces contact) were found in 100%, 32%, and 28% of patients, respectively. Seventy-six percent of patients demonstrated more than one lesion. Eighty percent of patients lived in Bangkok, and 44% of patients had a home near a farm or forest. Fluorescent lighting was used in the homes of 24 patients. All 25 patients were treated with topical steroid, and some received other supportive regimens. Two patients had post-inflammatory hyperpigmentation as a complication; only 7 of 25 patients attended the scheduled follow-up visit. CONCLUSION: In Thailand, PD presents throughout the year, but the most active month is December. Skin lesions vary from mild irritant dermatitis to severe dermatitis, and the average time to complete cure is 12 days. History and clinical manifestation are essential for accurate diagnosis.

Evaluation of Lymphocyte Migration to Induced Paederus Dermatitis: An Experimental Study in Rats.

BACKGROUND: Paederus dermatitis (PD) is a blistering disorder that is caused by a small insect of the genus Paederus, especially Paederus fuscipes. This study aimed to investigate the reaction of the adaptive immune system regarding the recruitment of CD3, CCR4, and CCR10 markers, which are specifically expressed on the surface of T lymphocytes. MATERIALS AND METHODS: In this experimental study, 24 female rats were divided into two groups: the test and the negative control. In the test group, PD was induced by making insects in contact with shaved rat skin. Biopsies were obtained 24, 72, and 120 h after induction. In the negative control group, physiological saline was applied. Specimens were evaluated by immunohistochemical staining method. Antibodies against CD3, CCR4, and CCR10 were used. Distribution and staining intensities of CD3, CCR4, and CCR10 markers were estimated by the H-score index and findings were analyzed using the Kruskal-Wallis and Wilcoxon statistical tests. RESULTS: Based on the results of immunohistochemistry, the expression of CD3, CCR4, and CCR10 in the test group at 24, 72, and 120 h compared to the control group showed significant increase (P = 0.0006, P = 0.001, and P < 0.0001), respectively. The peak of expression of all markers was at 72 h after exposure. Hematoxylin and eosin staining also confirmed the fact that the majority of the lymphocyte infiltration occurred at 72 h postexposure. CONCLUSION: The expression of CD3, CCR4, and CCR10 on cells present in PD lesions could indicate that T-lymphocytes are recruited to the site of inflammation by chemokine-chemokine receptor interactions and hence provide evidence for the response by the adaptive immune system following a PD.

Paederus Dermatitis: A Case Series.

Vorderman (1901) was the first to record blisters caused by beetles in medical literature. Blister beetle dermatitis is a cutaneous condition caused by the toxins released by blister beetles. The vesicant chemical in the body fluids of these insects causes an acute irritant contact dermatitis characterized by erythematovesicular lesions associated with burning sensation on exposed parts of the body. The aim of this study was to investigate the morphological patterns of blister beetle dermatitis. We conducted a 1-year (January-December 2014) prospective study of the clinical presentation of Paederus dermatitis noticed in urban and semiurban areas close to paddy fields in the Cauvery Basin, Mysuru, Karnataka. All patients with Paederus dermatitis attending the outpatient department of Department of Dermatology were recruited in the study with a total of 37 patients. Diagnosis was made on detailed history regarding onset of lesions, symptoms, as well as thorough clinical examination of the lesions. The peak time of presentation was June-September, the monsoon season in this part of India. The average duration of lesions at the time of presentation was 2-5 days. All patients had a history of burning and itchy sensation at night followed by full blown lesions the next morning, with the face, neck, and arms being the most common sites. Patients were predominantly males with the age range of 13-55 years. The most common presentations were linear erythematous plaques and erythematovesicles with a "burnt" appearance and a gray necrotic centre. "Kissing" lesions and periorbital involvement were seen in 5 and 6 patients, respectively. Species identification of the Paederus beetles was not done. Paederus dermatitis occurs in tropical regions. Awareness about the morphological patterns of the condition will prevent misdiagnosis. Simple preventive measures can be undertaken based on the behavioral pattern of this nocturnal beetle.

The Effects of Light and Height of Building in Attracting Paederus fuscipes Curtis to Disperse towards Human Residential Areas.

Paederus fuscipes Curtis is a nocturnal insect. The attractiveness of artificial light sources from residential premises eventually causes the risk of severe dermatitis effect, once Paederus is in contact with human skin. The objective of this study is to investigate whether the light and height factors of residential buildings and its' association to rice cultivation phases are primary reasons for P. fuscipes's mass dispersal into human residential areas. The study site was located in residential premises that were built adjacent to rice field areas (≈ 32-60 m and 164 m) north of the rice field located in Teluk Air Tawar, mainland of Pulau Pinang. Overall, both light sources and rice cultivation phases caused a significant effect for P. fuscipes beetles dispersal flight to invade human settlements. More P. fuscipes were captured near the bright light source with the highest number of beetles found during harvesting stage. Whereas, significantly higher number of P. fuscipes were captured at level 2 and 3 compared to ground and level 1 of the apartment building and P. fuscipes was also found significantly affected by the rice cultivation phases at different elevation levels. This indicates that bright light sources and higher elevation levels are the main factors in attracting P. fuscipes beetles to disperse and causes infestations in residential areas. This finding could create awareness among the public on P. fuscipes dispersal pattern.

[Vesicular contact dermatitis due to Paederus in Cameroon and review of the literature]. / Dermatite vésicante à Paederus au Cameroun et revue de littérature.

This irritant blister dermatitis is caused by the genus Paederus whose geographical distribution is worldwide, with a higher incidence in tropical areas. It is induced by direct skin contact with pederin, a blistering and caustic substance found in the abdomen (coelome) of Paederus insects (insect order Coleoptera: family Staphylinidae). The diagnosis is based on the presence of typical clinical features combined with compatible epidemiological features. Our goal is to describe the epidemiological and clinical features of this irritant contact dermatitis in Cameroon through a retrospective study conducted at the end of the rainy season at the Oku Hospital in Northwest Cameroon and to also include cases reported at the medical center of the French Embassy in Yaounde during this same timeframe. In addition, we conducted a literature review of paederus dermatitis. Nineteen patients were included in this study. More than half of the patients presented with more than two lesions predominantly localized to the face or the neck; less than half had complications manifesting as either localized or respiratory reactions and three patients presented periorbital involvement. This study confirms the presence of paederus dermatitis in Cameroon. It is mainly localized in the unusual geoclimatic region of the western high mountains within the country, as well as the usual warm, moist areas of Yaounde. The clinical evolution of this dermatitis is usually one of spontaneous and uneventful resolution with complications being rare. Curative treatment is one of localized topical therapies while oral antibiotic therapy should be reserved for more complicated cases.

The Influence of Weather and Lunar Phases on the Flight Activity of Paederus Rove Beetles (Coleoptera: Staphylinidae).

Despite the medical importance of Paederus beetles, no studies have studied the influence of the abiotic factors on the flight activity and nighttime dispersal of these insects in Brazil. Therefore, the influence of both climatic factors and moon phase on black-light catches of Paederus rove beetles was investigated. Paederus beetles were attracted to a black light source hourly from 1800 to 0600 hours, and data on weather conditions as well as moon phase data were taken for every sampling date. Overall, 543 individuals of Paederus beetles belonging to four species were captured: P. protensus, P. columbinus, P. brasiliensis, and P. mutans. Paederus beetles were mostly active in the warmest parts of the studied nights. Variations in nighttime temperature, relative humidity, wind speed, cloud cover, and moon phases appear not to affect Paederus flight. The diurnal temperature was observed to affect the night hourly dispersal of Paederus rove beetles as well as their distribution pattern during the entire period of study. The true environmental condition responsible for Paederus beetles seasonal pattern and daily night dispersal in northeastern Brazil were the annual moisture and drought cycles and the diurnal maximum temperatures, respectively. Significant trap catches were observed in the earliest hours after sunset (1800-2100), and people must be aware of this fact, as it can notably increase the risk of acquiring linearis dermatitis from the contact with large numbers of active Paederus.

Treatment of Paederus Dermatitis with Sambucus ebulus Lotion.

Paederus dermatitis is an irritant contact dermatitis due to accidental contact by a beetle belonging to the genus paederus. In this study, clinical efficacies of S. ebulus fruit extract solution in patients affected by paederus dermatitis were evaluated. A randomized double-blind, prospective, placebo-controlled clinical trial was performed in 62 patients with clinical symptoms and sings of dermatitis due to paederus beetles. The patients received either a topical solution of palemolin (a 5% S. ebulus fruit extract in ethanol 70%) or ethanol 70% topical solution thrice a day. Topical hydrocortisone ointment was prescribed for all patients. Palemolin was statistically more effective in controlling of burning, pain, inflammation, drying the wound, infections and acceleration of healing than control group (p ≤ 0.05). Specially in controlling of inflammation, palemolin had more significant efficacy (p < 0.001) than control group. About 63.6% of patients in palemolin group cured during first 24 h (versus 27.4% in control groups). The problems related to lesions in 93.9% of patients were eliminated completely during 48 hours after the beginning of the treatment by palemolin (versus 65.4% in control groups). Topical 5% solution of S. ebulus fruit extract is an effective pharmaceutical preparation in treatment of paederus dermatitis.

An outbreak of Rove Beetle dermatitis in Penang Hospital: A report of 37 cases

Background Rove beetle dermatitis is a peculiar form of acute irritant dermatitis following the contact with body fluid of an insect which is belonging to genus Paederus. This retrospective study is to evaluate the epidemiology and clinical manifestations of rove beetle dermatitis during the outbreak of rove beetle dermatitis in Penang (March 2009 - April 2009). Methods We describe 37 patients with clinical diagnosis of rove beetle dermatitis presented to our department. Only those patients with a definite history of contact with the insect were included in the study. Demographic characteristics, reason for referral and details of skin lesions were documented and analysed. Results Male patients outnumbered female patients - 21 males (56.8%); 16 females (43.2%). The mean age of patients was 28.3 years. Of the 37 patients, 18 patients (48.6%) were Malay, 14 Chinese (37.8%), 4 Indians (10.8%) and 1 foreigner (2.8%). The mean duration of lesions before presentation to our clinic was 3.4 days. The mean duration of lesions before presented to our clinic was 3.4 days. Symptom of burning sensation (25, 67.7%) was more pronounced than itching (6, 16.2%). Fourteen of our patients (37.8%) reported a positive family history. Clinically, the most common presentation consisted of linear, geographic, erythematous plaques with a ‘‘burnt’’ appearance. In 59.5% of patients, more than one lesion was present. Pustules and vesicles were seen in 12 (32.4%) and in 10 (27.1%) of the patients respectively. ‘‘Kissing lesions’’were seen in 5 (13.5%) patients. The neck and arms were the most common sites of involvement. Periorbital involvement occurred in 16.2% of patients. Only 8 patients (21.6%) were diagnosed to have “insect related dermatitis” at initial presentation. No one was referred as “rove beetle dermatitis”. Conclusion Rove beetle dermatitis is a common condition. Awareness of these condition and its clinical features will prevent misdiagnosis and unnecessary worry.

A Case of Paederus Dermatitis

Paederus dermatitis is a characteristic irritant contact dermatitis caused by paederin which is a chemical substance released by insects of the genus Paederus. Erythematous vesiculobullous eruption with a burning sensation occur within 24 hours after contact with Paederus. This dermatitis is frequently seen in regions with hot, tropical climates such as Africa and the Middle East. There have been a few reports of Paederus dermatitis in Korea. We recently had a patient with Paederus dermatitis who traveled to Kenya. We would like to highlight an awareness of this peculiar dermatitis due to the increasing numbers of travelers visiting tropical countries.

Blistering Beetle Dermatitis: An Outbreak.

BACKGROUND: Blister beetles, which are abundant in Madhya Pradesh and Punjab cause peculiar skin lesions. We came across large number of such cases. METHOD: This descriptive study comprised 46 cases of Blistering beetle dermatitis who presented to skin OPD, over a period of one month from 17 April to 15 May 2002. RESULT: All cases belonged to one company of soldiers deployed near an agricultural land. Of the total of 245, 46 personnel suffered from blistering beetle dermatitis with an incidence of 18.7%. A thorough epidemiological investigation was undertaken and beetles of Paederus Fucipes were found incriminating. Further spread was effectively controlled by timely spray of Baygon and Malathion over the infested land. CONCLUSION: In an outbreak of bizarre dermatitis, diagnosis of blistering beetle dermatitis should be kept in mind. Timely diagnosis, epidemiological investigation and insecticide spraying brings down the incidence of new cases.

A Case of Paederus Dermatitis due to paederus fuscipes / 대한피부과학회지

Paederus dermatitis is a linear and self-healing blistering disease of the skin caused by contact with insects belonging to genus Paederus(Coieoptera : Staphylinidae). There have been only a few reports of paederus dermatitis in the southern part of Korea since 1968. We recently experienced a case of paederus dermatitis due to contact by P. fuscipes.

Epidemiologic Study of Paederus Dermatitis Prevailing in the Midwest Area of Kyungpuk Province / 대한피부과학회지

BACKGROUND: Paederus derriattis is a peculiar linear lesion caused by an insect belonging to genus Paederus, family Staptylinidae, order Coleoptera. The deliberate or accidental contact of crushed coelomic fluid of th insect, on the skin causes acute lesions due to a t.oxin(pederin) being released. OBJECTIVE: The study was nade in order to investigate an epidemic status of the peculiar der matitis and its causative agent of factor prevailing in the midwest area of Kyungpuk province. METHODS: We performed field approaches on 633 cases(M: 303, F: 330) including cases enrolled in a local clinic, teamiring up with a local skin clinician over the 3-month period of August November in 1994. RESULTS: 1. The captive insect causing the present dermatits, was identified as Paederus fuscipes(PF). The epidemic might be attributeid to the climatic conditions with higher temperature than usual during the period of July-eary September in the past year by 3-4degrees C as well as a lower relative humidity. The active temperature zone for PF was presumed to be about 15.5+1.2degrees C to 28.9+1.0degrees C 2. There was the highest p;evalence of 412 cases(65.1%) in early September, followed by mid September, late August, early October and mid August in a small number of cases in decreasing order. The cases were not found after mid October. 3. All age groups were evealy represented. The sex ratio was 1: 1.1 with little difference. The majority of cases lived in Kiriich on city(80.3%), with a lesser outbreak in the neighboring coun ties and Kumi city. 4. The preferred site was the mainly exposed area such as face, neck and extremities. The number of lesion was single(60%) and multiple(40%). The lesion showed a common linear con figuration and acute irritant contact dermatitis consistent with the histologic finding. CONCLUSION: The unusual wiather conditions and poor environmental hygiene help to develop an ecosystem breakdown, which, in turn, sometimes influences the innocuous insects life to be harm ful being on humans, as like outbreak of PF dermatitis.

Clinical and Entomological Studies of Paederus Dermatitis / 대한피부과학회지

Paederus dermstitis (or dermatitis linearis), caused by the insect genus Paederus, is characterized by linear erythernatous, vesicopustular lesions. In 1968, we proved that causative agent is Paederus fuscipes. During the 20-year period since then (from June 1968 to September 1988), we have experienced 156 cases of the diseaes in our clinic, and the clinical features were studied with the following results. (1) They were found only during summer months from June to September. Most prevalent in June(47%), followed by August, July and September, in decreasing order. (2) People in their twenties were affected most often(10%), with females outnumbering males, by approximately 2.8 to 1. (3) The lesions were found exclusively over exposed areas, such as face, neck, and extremities (4) Experiments on a volunteer revealed that the same skin lesions as in the patients can be produced by rubbing the anal portion of the insect. (5) Spongiosis and subcorneal pustule of epidermis were the main histopathological findings. (6) The insects appear ant-like and measures 6.5 to 7mm in length. It has a black, round head with pslpuli black, rectangular, short elytra, yellowish brown pronotum and abdomen composed of 6 segments, of which two caudal ones(hypopygium) were dark brown. The meso and metathorax, and the lower ends of the femurs in meso and metapedes appear dark brown. (7) Wide use of potent pesticides, herbicides, or insecticides as well as the urbanization may have reduced the out breaks of the disease in recent years.