Dermatobia hominis 'the human botfly' presenting as a scalp lesion.

Owing to increasing international travel, physicians will encounter more infectious diseases acquired overseas, which may be bacterial, fungal or parasitic in nature. 1 Knowledge of the geographic distribution of specific diseases permits the formulation of a differential diagnosis in the context of clinical presentation. Parasitic infestations of the maxillofacial tissues can be caused by a host of different ectoparasites, for example, myiasis, a frequently misdiagnosed disease of tourists returning from exotic locations. For those natives and travellers who are subject to these 'infestations', the experience can be both alarming and very distressing.

Fluctuating lesion of the scalp after a journey to the tropics: a case of furunculoid myiasis.

Fluctuating lesions or furuncles of the scalp occur frequently in dermatological practice. This clinical condition is often caused by gram positive bacteria (e.g. staphylococcal or streptococcal skin infection) or fungal infection (e.g. Kerion celsi). However, a rare diagnosis such as myiasis might be considered, especially if a journey to an endemic area is reported. Herein, we present a case of furunculoid myiasis of the scalp and review the pathogenesis and therapeutic options to treat this condition.

Comparative study of the claws of Pediculus humanus capitis between archaeological and modern specimens.

Metric data of the claws of archaeological specimens of Pediculus humanus capitis (dating between 1500 B.C. and A.D. 1500) and modern lice specimens coming from school children were analyzed and compared. Both sets of samples come from Arica in northern Chile. The overall sample is comprised of 14 archaeological specimens (6 females and 8 males) of Pediculus humanus capitis and 22 modern specimens (13 females and 9 males). All specimens were studied with scanning electron microscopy (SEM), uncoated, using variable pressure mode. The objective of this study was to metrically analyze the first couple of clutches of ancient and modern adult lice specimens (width and length of the tibio-tarsal claw and tarsus length) to test if morphological changes have taken place throughout time in these anatomical elements. We found that archaeological male and female specimens presented significant differences in the tibio-tarsal width (right and left). When comparing data between archaeological and modern male specimens, statistically significant differences were found in almost all the parameters studied, except for the right tarsal length. On the other hand, archaeological and modern female specimens showed no statistically significant change in the variables studied. In brief, our data suggest that modern male specimens have undergone a process of claw reduction, but females have maintained the same dimensions.

Tick Bite Alopecia: A Report and Review.

Tick bites can cause a number of local inflammatory reactions, which are often difficult to differentiate from those induced by other arthropod bites or stings. These include erythematous nodular or pustular lesions, erosive plaques, annular lesions of erythema chronicum migrans, and both scarring and nonscarring inflammatory alopecia. We report a case of nonscarring alopecia in a 21-year-old male who reported a recent history of tick bite to the scalp. The biopsy demonstrated a dense pseudolymphomatous inflammatory infiltrate with numerous eosinophils associated with hair follicle miniaturization and an elevated catagen-telogen count. Signs of external rubbing, including lichen simplex chronicus and the "hamburger sign", were also visualized and are indicative of the associated pruritus. To the authors' knowledge, this is the fifth report of nonscarring tick bite alopecia in the literature and the first in an adult patient. This text will review the classic clinical presentation, histologic findings, and proposed mechanism of tick bite alopecia.

Cutaneous larva migrans on the scalp: atypical presentation of a common disease.

Cutaneous larva migrans is a pruritic dermatitis due to the inoculation of helminths larvae in the skin, and it often occurs in children in tropical and subtropical areas. The authors describe an atypical case of cutaneous larva migrans in a 11 year-old child with scalp involvement, an unusual topography for this lesion.

Cutaneous larva migrans on the scalp: atypical presentation of a common disease

Cutaneous larva migrans is a pruritic dermatitis due to the inoculation of helminths larvae in the skin, and it often occurs in children in tropical and subtropical areas. The authors describe an atypical case of cutaneous larva migrans in a 11 year-old child with scalp involvement, an unusual topography for this lesion.

[Epidemiological study of Pediculosis in elementary schools of Arica, northern Chile]. / Estudio epidemiológico de la Pediculosis en escuelas básicas del extremo norte de Chile.

UNLABELLED: Pediculosis is an ectoparasitosis infestation that has not received much attention in northern Chile despite it is a common reoccurring condition among school-age children. The objective of this study is to determine the prevalence of Pediculus humanus capitis infestation in elementary schools of Arica. PATIENTS AND METHOD: A group of 665 elementary school students from the Province of Arica were screened between August and November 2010; 467 children who met the inclusion criteria were selected. After parents and students signed an informed consent, the diagnosis was carried out through examination of the head with naked eye in each participating school, recording the presence of Pediculus humanus capitis, infestation level and parasite stage. RESULTS: 40.3% (188) of the children presented Pediculosis; the six schools studied were affected. Pediculosis infestation in girls reached 55.2% (138/250) and 23% (50/217) in boys. CONCLUSION: The school population of Arica is significantly affected by Pediculosis and its prevalence is similar to other regions.

Amazonian head lice-specific genotypes are putatively pre-Columbian.

Head and body lice are strict obligate human ectoparasites with three mitochondrial phylotypes (A, B, and C). Using molecular methods for genotyping lice (Cytochrome b and multi-spacer typing), and comparing our results with all the sequences of human lice that were genotyped previously, we assessed the presence of a specific American genotype that most likely predates the Columbian era in head lice collected from Amazonia.

Dermoscopy features for the diagnosis of furuncular myiasis.

We describe a 56-year-old Brazilian woman presenting three nodular lesions on the scalp. Dermoscopy of all lesions showed a creamy-white body with central bird's feet-like structures surrounded by a thorn crown, corresponding to the posterior segment of the Dermatobia hominis larvae. These novel dermoscopic features allowed us to easily diagnose furuncular myiasis.

Dermoscopy features for the diagnosis of furuncular myiasis / Características dermatoscópicas para diagnosticar miíase furunculóide

We describe a 56-year-old Brazilian woman presenting three nodular lesions on the scalp. Dermoscopy of all lesions showed a creamy-white body with central bird's feet-like structures surrounded by a thorn crown, corresponding to the posterior segment of the Dermatobia hominis larvae. These novel dermoscopic features allowed us to easily diagnose furuncular myiasis.

Descrevemos o caso de uma paciente brasileira de 56 anos de idade do sexo feminino que apresentou três lesões nodulares no couro cabeludo. A dermatoscopia das lesões mostrou um corpo branco-amarelado com uma estrutura central similar a pés de pássaro, circundado por uma coroa de espinhos, correspondendo ao segmento posterior das larvas de Dermatobia hominis. Estas novas características dermatoscópicas nos permitiram diagnosticar facilmente miíase furuncular.

Effectiveness of lotions based on essential oils from aromatic plants against permethrin resistant Pediculus humanus capitis.

In Argentina, field populations of the head louse Pediculus humanus capitis De Geer (Phthiraptera: Pediculidae) have developed resistance to permethrin and other pyrethroids. Thus, the aim of this work was the development of a lotion containing essential oils from plants and an alcoholic coadjuvant to improve biological effect. Ethanol + isopropanol (1 + 1 in volume) 50% in water and ethanol 96% were taken as bases for preparation of experimental lotions containing essential oils from plants. We found that experimental lotions containing lavender, peppermint and eucalyptus oils in a 5% composition and the combination of eucalyptus and peppermint in a total concentration of 10%, dissolved in 50% ethanol + isopropanol (1 + 1) in water, showed the best knockdown effect. On the other side, lotion containing peppermint oil and eucalyptus oil (1 + 1) 10%, dissolved in ethanol 96%, showed to be as effective as the best commercial lotion now available in Argentina. Furthermore, addition of 1-dodecanol in all cases increased the effectiveness of all the experimental lotions. This difference is significantly important for 1-dodecanol concentration of 10%, reaching a toxic activity compared to the best commercial lotion available in the market.