Therapeutic management of DRESS: a retrospective study of 38 cases.

BACKGROUND: There is no consensus regarding treatment for drug reaction with eosinophilia and systemic symptoms (DRESS). OBJECTIVES: We report a single-center observational series of therapeutic management of DRESS. METHODS: We examined data for 50 consecutive patients admitted from March 2005 to June 2009 with a discharge diagnosis of DRESS (RegiSCAR score). RESULTS: For the 38 patients with a DRESS score of 4 or more, topical steroid treatment alone was initiated in 66% of cases. On admission, 13 patients received systemic steroids; in 7 of them, systemic steroid treatment was initiated or maintained for life-threatening organ failure, with kidney, lung, and/or nervous system involvement. Complications of DRESS, such as relapse, viral reactivation, and sepsis, were less frequent with topical steroid than with systemic steroids. None of the patients died during their stay in hospital. LIMITATIONS: Retrospective nonblinded design and dermatologic recruitment are limitations. The variables underlying the choice of treatment study were not analyzed. CONCLUSIONS: Systemic steroids may not be required for the management of mild forms of DRESS, and may thus be reserved for more severe cases. Prospective studies are required to evaluate strategies for treating DRESS.

Toxic epidermal necrolysis, DRESS, AGEP: do overlap cases exist?

BACKGROUND: Severe cutaneous adverse reactions to drugs (SCARs) include acute generalized exanthematous pustulosis (AGEP), drug reaction with eosinophilia and systemic symptoms (DRESS) and epidermal necrolysis (Stevens-Johnson syndrome-toxic epidermal necrolysis [SJS-TEN]). Because of the varied initial presentation of such adverse drug reactions, diagnosis may be difficult and suggests overlap among SCARs. Overlapping SCARs are defined as cases fulfilling the criteria for definite or probable diagnosis of at least 2 ADRs according to scoring systems for AGEP, DRESS and SJS-TEN. We aimed to evaluate the prevalence of overlap among SCARs among cases in the referral hospital in France. METHODS: We retrospectively analyzed data for 216 patients hospitalized in the referral centre over 7 years with a discharge diagnosis of AGEP (n = 45), DRESS (n = 47), SJS-TEN (n = 80) or "drug rash" (n = 44). Each case with detailed clinical data and a skin biopsy specimen was scored for AGEP, DRESS and SJS-TEN by use of diagnostic scores elaborated by the RegiSCAR group. RESULTS: In total, 45 of 216 cases (21%) had at least 2 possible diagnoses: 35 had a single predominant diagnosis (definite or probable), 7 had several possible diagnoses and 3 (2.1% of 145 confirmed SCARs) were overlap SCARs. CONCLUSIONS: Despite ambiguities among SCARs, confirmed overlap cases are rare. This study did not avoid pitfalls linked to its retrospective nature and selection bias. In the acute stage of disease, early identification of severe ADRs can be difficult because of clinical or biologic overlapping features and missing data on histology, biology and evolution. Retrospectively analyzing cases by use of diagnostic algorithms can lead to reliable discrimination among AGEP, DRESS and SJS-TEN.

Permethrin and malathion resistance in head lice: results of ex vivo and molecular assays.

BACKGROUND: Treatment of head lice infestation relies on the application of topical insecticides. Overuse of these products has led to the emergence of resistance to pyrethroids and malathion worldwide. Permethrin resistance in head lice is mostly conferred by the knockdown resistance (kdr) trait. OBJECTIVE: To evaluate the occurrence of permethrin- and malathion-resistant head lice in Paris. METHODS: A prospective survey was conducted in 74 elementary schools. Live lice collected on schoolchildren were randomly selected and submitted to ex vivo bioassays or underwent individual DNA extraction. A fragment of kdr-like gene was amplified and compared with wild-type sequences. RESULTS: Live head lice were detected in 574 children. Ex vivo assays showed no surviving lice after a 1-hour contact with malathion while most lice died after a 1-hour exposure to permethrin and piperonyl butoxide (85.7%, 95% confidence interval [CI]: 83.9-87.5). Among the 670 lice with workable DNA sequences, 661 lice (98.7%, 95% CI 97.7-99.3) had homozygous kdr mutations. LIMITATIONS: The findings of this large-scale survey of the occurrence of insecticide-resistant head lice indicated a major insecticide pressure in the study population, but it was not sufficient to draw conclusions about other populations. The presence of T917I-L920F mutations in kdr gene may not correlate with treatment failure in prospective studies. CONCLUSION: The high occurrence of kdr mutant allele suggests that insecticide resistance was already strongly established in the studied population. This finding must be interpreted with caution as it may not be predictive of treatment failure.

No evidence of Bartonella quintana but detection of Acinetobacter baumannii in head lice from elementary schoolchildren in Paris.

The human body louse is the only known vector of Bartonella quintana. However, the presence of this bacterium has recently been detected in the head lice of homeless individuals and Nepalese slum children. Previous studies have reported the isolation of Acinetobacter baumannii from the body lice of homeless individuals. An epidemiological survey including 74 schools was conducted between 2008 and 2009 in Paris. After a first visual examination, the hair of children with suspected pediculosis was combed with a fine-tooth comb to collect live adult head lice. Molecular studies were performed on randomly selected DNA samples to detect B. quintana and A. baumannii by specific quantitative real-time PCR. Among a collection of 288 DNA samples, B. quintana was not detected, but A. baumannii was detected in 95 DNA samples (33%). Further study is needed to determine the significance of the finding of A. baumannii in head lice.

High frequency of mutations associated with head lice pyrethroid resistance in schoolchildren from Bobigny, France.

Resistance of head lice to pyrethroids induces difficult therapeutic problems. Previous studies demonstrated that this resistance was present in a French urban area, but its prevalence needed to be more precisely evaluated in terms of genotyping lice collected from more infested children over a certain period of time. We monitored the presence of the head lice kdr-like haplotype of the voltage-gated sodium channel alpha-subunit gene in schoolchildren seen three times on a 6-wk period. The prevalence of pediculosis was 2.39% (n = 1551). Genotyped lice (n = 167) were homozygous resistant in all but one pupil. The high frequency of the mutant haplotype (0.93) advocated for the abandonment of pyrethroid insecticides in this area and for the consideration of other treatment options.

Scabies in healthcare settings.

PURPOSE OF REVIEW: In industrialized countries, epidemics of scabies are mainly described within families or in institutions such as healthcare settings. Control of institutional scabies is associated with a considerable working and economic burden, but guidelines for the management are scarce. RECENT FINDINGS: The prevalence of institutional scabies is probably underestimated. Identified risk factors for institutional scabies outbreaks include the institution type, extensive physical contact with patients and movement of patients, the existence of crusted scabies, a long diagnostic delay and failures in implementation of infection control or treatment plans.Atypical clinical features (hyperinfestation, scabies in the elderly or in children) may be misdiagnosed. Control of institutional scabies outbreaks relies on prompt recognition of the index case, constitution of an outbreak management team, determination of the extent of the outbreak and risk factors for spread, immediate implementation of infection control practices, adequate education of all involved persons, simultaneous treatment of cases and of all exposed individuals and concomitant environmental disinfection. Prolonged surveillance is imperative to eradicate scabies. SUMMARY: The inclusion of institutionalized patients in randomized controlled trials would be beneficial as present data concerning scabicide effectiveness are obtained from trials that recruited individual participants and do not take into account a global strategy.

Two cases of cellulitis in the course of African tick bite fever: a fortuitous association?

In African tick bite fever (ATBF), inoculation eschar - resulting from disruption of the cutaneous barrier - may be a risk factor for cellulitis. We report 2 cases of ATBF associated with cellulitis. A 77-year-old woman was referred for severe leg cellulitis upon returning from sub-Saharan Africa. She developed erythematous macules. Rickettsia africae was detected by PCR assay from a skin biopsy specimen, and ATBF diagnosis was confirmed. A 75-year-old man was hospitalized after his return from Zimbabwe for a maculopapular exanthema and erysipelas-like rash of the leg. The diagnosis of cellulitis associated with ATBF was confirmed by PCR and serological methods. Both patients were treated for ATBF and cellulitis by a combination of doxycycline and beta-lactam antibiotics, and both had a good recovery. Inoculation eschar may be a risk factor for cellulitis; thus, we hypothesize a non-fortuitous association between ATBF and cellulitis.

Detection of pyrethroid resistance gene in head lice in schoolchildren from Bobigny, France.

The head louse, Pediculus humanus capitis (De Geer), is an hematophagous ectoparasite that affects mainly children. Resistance to insecticides belonging to pyrethroids and other pediculicides, such as malathion, is responsible for frequently reported treatment failures. Recent studies showed that a M815I-T929I-L932F kdr-like mutation in the voltage-gated sodium channel alpha-subunit gene was associated with permethrin resistance in head lice from several countries worldwide. We searched for the presence ofpyrethroid resistance gene in head lice populations obtained in schoolchildren in an urban area of France. All the 15 primary schools of Bobigny, a city located 3 km north of Paris, were selected to participate. Of 3,493 children enrolled, 3,345 (95.8%) children were screened for head lice by using fine-toothed antilouse combs. Live head lice were detected in 112 (3.3%) of children screened. A subsample of 90 lice was processed for DNA study. The amplification of a 332-bp portion of the kdr-like gene spanning the codon 929 was performed, and polymerase chain reaction products were submitted to the restriction enzyme SspI. Twenty of these lice (22.2%) were homozygous susceptible, 33 (36.7%) were homozygous resistant, and 37 (41.1%) were heterozygotes. Globally, the frequency of the T929I mutation was 0.57. The prevalence of pediculosis in schoolchildren of Bobigny seemed relatively low in comparison with findings of other European studies. The presence of the T929I mutation associated with permethrin resistance probably reflected the frequent local use of this insecticide. Further studies are now required to evaluate the prevalence of the kdr-like mutant allele in head lice in French schools.

Pott's disease occurring after percutaneous vertebroplasty: an unusual illustration of the principle of locus minoris resistentiae.

We report an unusual case of a multifocal tuberculous spondylitis that has been diagnosed after several percutaneous vertebroplasty. This event supports the theory that surgical or radiological intervention such as a percutaneous vertebroplasty should be considered as an intentional traumatism that can lead to the initiation of a locus minoris resistentiae, probably by reactivating an inactive tuberculous lesion.