Anthony M. R. Downs

Head Lice: Prevalence in Schoolchildren and Insecticide Resistance

Several small case studies have shown a therapeutic response for oral cotrimoxazole22xShashindran, C.H. et al. Br. J. Dermatol. 1978; 98: 699Crossref | PubMedSee all References22, oral and topical ivermectin23xGlaziou, P. et al. Trop. Med. Parasitol. 1994; 45: 253–254PubMedSee all References, 24xYoussef, M.Y. et al. Am. J. Trop. Med. Hyg. 1995; 53: 652–653PubMedSee all References, topical crotamiton25xKaracic, I. and Yawalkar, S.J. Int. J. Dermatol. 1982; 21: 611–613Crossref | PubMedSee all References25, and topical 1% copper oleate shampoo26xIannantuono, R.F. et al. Adv. Ther. 1997; 14: 134–139See all References26. We have also assessed the novel flea adulticides, fipronil and imidicloprid, and found them to be 97 and 100% effective in vitro against head and body lice (unpublished). Alternative carbamates such as propoxur or alternative organophosphates such as temephos27xMazzarri, M.B. and Georghiou, G.P. J. Am. Mosq. Control Assoc. 1995; 11: 315–322PubMedSee all References27 may be unaffected by the resistance mechanism against malathion. All these agents may have a place in the control of head lice. If a new agent is introduced into the human market, it is likely that head lice will eventually develop resistance. To reduce chronic use, and so slow the development of resistance, an option would be to have all insecticides available by prescription only. Strategies should be used to keep head lice levels to a socially acceptable minimum level. Strategies such as educational campaigns by community nurses, doctors and school teachers should promote head lice eradication. Although it is doubtful whether regular combing will cure a head lice infestation, it is likely to reduce the numbers of lice carried and should be promoted as the first line of treatment before insecticides. Children who fail to clear their infestations should be targeted by school nurses for treatment. All family members and classmates should be assessed for asymptomatic carriage. Ideally, all schoolchildren should be at separate desks during lessons to reduce transmission of head lice. Given the national rise in the prevalence of head lice and in insecticide sales, it is likely that the resistance phenomenon we have observed in Bristol and Bath is nationwide, and will require national changes in attitudes towards the treatment and surveillance of this ectoparasite.

Colophony allergy: a review

Colophony is a complex mixture of over 100 compounds derived from pine trees. It has countless applications at home and at work and exposure to colophony and modied‐colophony is universal. It is the oxidation products of unmodied and modied colophony and some of the new resin acids synthesized during modication that are the principle allergens in colophony. The neutral fraction may account for a small % of positive reactions. When screening for allergy using unmodied gum rosin, allergy to modied rosin will not be revealed. When patients react to both materials, it is probably due to unmodied colophony present in both, rather than a cross‐reaction. Relevant positive reactions may be missed if only colophony 20% pet. is relied upon as the screening material.

Pentaerythritol-esterified gum rosin as a sensitizer in Granuflex hydrocolloid dressing.

Of the last 17 consecutive patients between 1996 and 1999 patch tested to GranuflexA hydrocolloid dressing in our department, 4 (24%) have been positive to colophony, AbitolA and GranuflexA, 1 (6%) to AbitolA and GranuflexA and 12 (70%) to GranuflexA alone. Fully hydrogenated pentaerythritol-esterified gum rosin (PEGR), manufactured by Hercules Inc., Delaware, USA, is used as the sticky agent for GranuflexA. When PEGR was substituted for colophony as a bow resin for colophony-sensitive violinists, they were able to tolerate regular exposure to PEGR without relapse of their contact dermatitis (1). Modified gum rosins, however, are rarely pure and contain some unmodified rosin – up to 6.2% abietic acid in the case of fully hydrogenated PEGR (2). Reactions previously attributed to PEGR have all been accompanied by positive reactions to colophony 20% pet. and could, therefore, have been due to the unmodified colophony fraction in the commercial product (2–4): we therefore recalled 7 GranuflexA patients for further patch testing.

Contact sensitivity and systemic reaction to pseudoephedrine and lignocaine

There are 4 cases reported of generalized erythema, joint swelling, tachycardia and rigors with oral pseudoeph‐edrine (1–3), many cases of non‐purpuric fixed drug eruption from oral pseudoephedrine (3); and 2 cases of positive patch tests to pseudoephedrine, 1 after a fixed drug eruption (3), and 1 after a generalized eczema (4). There are reports of adverse reactions to lignocaine fol‐lowing its use as a subcutaneous injection, deep dental infiltration, and as a topical application (5). Adverse re‐actions to lignocaine are quite common, but immune pathology cannot usually be demonstrated. Adverse re‐actions that are mediated by the immune system are generally of the immediate type (Type I), whilst delayed allergy is rare (6).

Dicaprylyl maleate – an emerging cosmetic allergen

Dicaprylyl maleate (DCM) has been reported rarely as a cause of allergic contact dermatitis. The objectives of this study were to identify patients from multiple centres with allergy to DCM in cosmetic products confirmed by patch testing and, in addition, to investigate the effect of testing with aged DCM. This is an international multicentre study of 22 patients with 26 reactions to products containing DCM. Patch testing was carried out to ingredients including DCM obtained from the manufacturer. Further testing was carried out with deliberately aged DCM in a sample of patients. 22 patients had clinical and positive patch test reactions at 4 days to a total of 26 cosmetic products containing DCM. 5 patients did not react to DCM prepared by the manufacturer from concurrent factory stock but did have positive reactions to a deliberately aged batch of DCM. DCM is an emerging cosmetic allergen. Testing with aged material yields a greater number of positive results. Co‐operation between cosmetics manufacturers and clinicians is important in the identification of new allergens.

Contact sensitivity in patients with oral symptoms

Patients and Methods 15 patients were referred during 1995–97: 6 by dermatologists and 9 from the Department of Oral Medicine, University of Bristol. Each patient was patch tested with the European standard series, facial and preservatives series, dental series, perfumes and flavourings series (individual constituents of perfume mix, benzylaldehyde, benzylcinnamate, sorbitan sesquiolate, geranium oil 1% and vanilla oil 10%), our own oral series (peppermint oil, menthol, propolis, dichlorophene, hexachlorophane, PABA, Eusolex 6007, anethole, chlorhexidine and titanium dioxide) and the patient’s own toothpaste 50% pet. Additional patch tests were applied if indicated.

Palmoplantar dermatitis may be due to phenol‐formaldehyde resin contact dermatitis

Both mercaptobenzothiazole (MBT) and p-tert-butylphenol-formaldehyde resin (PTBP) cause shoe dermatitis (1). Concurrent hand dermatitis occurs in MBT allergy and hand dermatitis may present secondarily to a primary contact dermatitis of the feet (2). Occupational hand dermatitis from phenol-formaldehyde resins is recognized (3). Palmo-plantar dermatitis from phenolformaldehyde resins could present in a similar frashion to MBT allergy. We assessed 7 consecutive cases of foot dermatitis from phenol-formaldehyde resins to see if hand dermatitis was also a presenting feature.

Scleroatrophic syndrome of Huriez in an infant.

Abstract: We present a 3‐year‐old boy with scleroatrophic syndrome of Huriez, a rare autosomal dominant condition with only seven affected families worldwide. Although assumed to occur from birth, an evolving case has not previously been documented. Infants do not possess the focal areas of keratoderma on the palms or soles; these develop in adult life. Of particular interest is the high incidence of squamous cell carcinomas that arise from the scleroatrophic skin.

IgG latex RAST is not a speci c marker for latex Type I hypersensitivity

A 57-year-old woman was seen with lesions of erythema multiforme (EM) on the trunk and extremities that had started a few days earlier. She had been taking tribenoside (HemocuronA: Amatou Pharmaceutical Co. Ltd., Osaka) 200 mg t.d.s. orally for the treatment of hemorrhoids for 10 days. Histological findings were of papillary edema and perivascular lymphohistiocytic infiltration. Patch tests with tribenoside 10% and 1% pet. showed erythema at D2 and D3, 5 control subjects being negative to the same concentrations.