Family rash

Abstract

A healty 35-year-old woman suddenly developed a papular rash with linear disposition, involving predominantly her arms. She had no history of allergies and did not take any medication; moreover she did not complain about any other symptom. The woman was referred to a dermatologist. She underwent a skin biopsy, with the hypothesis of Lichen striatus or Herpes zoster. The histologic examination did not confirm these assumptions, showing a dermal infiltrate of T-lymphocites in perivascular space and close to skin appendages, and a mild interstitial edema with mucoid and basophil appearance. In the next two weeks, the woman spent her holidays out of home, and her skin lesions progressively improved. When she went back home, she slept for a night with her daughter, in the same bed. The following day, they both showed a maculo-papular and itchy rash on their arms and chest (fig. 1-2). They found on their bedding some small, reddish-brown insects and their eggs (fig. 3).Fig. 2Skin lesions, motherView Large Image Figure ViewerDownload Hi-res image Download (PPT)Fig. 3Insects in the patients'bedding.View Large Image Figure ViewerDownload Hi-res image Download (PPT) What is the diagnosis? Bedbug rash Bedbug infestations are common and widespread with a worldwide diffusion and a significant increase in recent years. Cimex lectularius (the common bedbug) is a nocturnal, hematophagous ectoparasite living in human-related environments with worldwide circulation[1]Goddard J Bugs deShazo R.Bed (Cimex lectularius) and clinical consequences of their bites.JAMA. 2009; 301: 1358-1366Crossref PubMed Scopus (249) Google Scholar. The usual skin lesion appears several hours after the bite and is a itchy erithematous papula or wheal (2-8 mm), with a central hemorrhagic crust. Lesions are multiple, sometimes located on a line or in clusters. Head, neck, arms, legs and waistline are frequently involved. Bullous rash may develop[2]Leverkus M Jochim RC Schäd S et al.Bullous allergic hypersensitivity to bed bug bites mediated by IgE against salivary nitrophorin.J Invest Dermatol. 2006; 126: 91-96Abstract Full Text Full Text PDF PubMed Scopus (75) Google Scholar. Systemic immuno-mediated reactions (anaphylaxis, asthma, and generalized urticaria) are rare[1]Goddard J Bugs deShazo R.Bed (Cimex lectularius) and clinical consequences of their bites.JAMA. 2009; 301: 1358-1366Crossref PubMed Scopus (249) Google Scholar, as well as malaise, fever and hypereosinophylia3Liebold K Schliemann-Willers S Wollina U Disseminated bullous eruption with systemic reaction caused by Cimex lectularius.J Eur Acad Dermatol Venereol. 2003; 17: 461-463Crossref PubMed Scopus (48) Google Scholar, 4Phan C Brunet-Possenti F Marinho E Petit A Systemic Reactions caused by bed bug bites.Clin Infect Dis. 2016; 63: 284-285Crossref PubMed Scopus (5) Google Scholar. Diagnosis may be difficult in the absence of bedbug discovery. Skin site (any exposed part of the body), distribution (lines or clusters), associated symptoms (itch without pain) and time of onset (in the morning upon awakening) can make the lesions suggestive of bedbug rash and should prompt advice to investigate the home for evidence of bedbugs. Starting a pharmacological treatment without a correct diagnosis of lesions due to hematophagous parasites would hide signs and symptoms, without being able to operate on the causes of the disease. In our case-report, skin lesions were confluent and they did not have a central hemorragic crust: other dermatological diseases were hypothesized and diagnosis was delayed. Treatment of bed-bug skin reactions is symptomatic and includes antihistamines and corticosteroids in order to reduce inflammation and itch. Pruritic lesions may cause scratching injuries with superinfection and consequently impetigo. Bed-bug eradication is required to control the disease. Given the worldwide diffusion, doctors should be aware of this clinical entity in order to avoid unnecessary tests and treatments. In our case, mother and daughter were treated with antihistamine medications. Bedbugs eradication in the infested room using vacuum cleaners and textils cleaning was performed. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.