Biomedical subjects
D J Todd
Publications and source records attributed to D J Todd.
Subcorneal pustular dermatosis and IgA paraproteinaemia: response to both etretinate and PUVA.
A non-insulin dependent male diabetic is reported with subcorneal pustular dermatosis associated with intraepidermal IgA deposits and a benign IgA paraproteinaemia. Treatment with dapsone and etretinate was reasonably effective, but etretinate had to be discontinued due to the development of diffuse idiopathic skeletal hyperostosis. His subcorneal pustular dermatosis subsequently flared and was troublesome for 2 years until he was commenced on PUVA, with excellent response.
Acromegaly and psoriasis.
A 56-year-old man with long-standing chronic plaque psoriasis was noted to be acromegalic. Investigations confirmed the presence of a large pituitary adenoma and following treatment of this by hypophysectomy his psoriasis cleared dramatically within 3 weeks.
Treatment of chronic varicose ulcers with pulsed electromagnetic fields: a controlled pilot study.
To evaluate the efficacy of pulsed electromagnetic fields (PEMF) in healing of chronic varicose ulcers, 19 patients with this condition were included in a double-blind controlled clinical trial. All patients received standard ulcer therapy throughout the duration of the study and were randomly divided into two groups to receive either active or inactive PEMF therapy. Active therapy was provided by the use of a pait of helmholtz coils on a twice weekly basis over a five week period and inactive therapy was provided on an identical regimen with identical coils wound so that no magnetic field was produced when an electric current was passed through them. The clinician and patients were unable to distinguish the active or inactive coils. No statistically relevant difference was noted between the two groups in the healing rates of the ulcer, change in the lower leg girth, pain or infection rates. However there was a trend in favour of a decrease in ulcer size and lower leg girth in the group treated with active PEMF. As PEMF is a novel treatment for chronic varicose ulcers, more work needs to be done to establish treatment parameters and its usefulness in the treatment of this condition.
Erythropoietic protoporphyria. The problem of a suitable screening test.
Erythropoietic protoporphyria (EPP) is characterized by increased red cell protoporphyrins and is included in the differential diagnosis of children presenting with photosensitivity. In the past 20 years, using the traditional solvent extraction qualitative screening test for blood porphyrins, the diagnosis of EPP had been missed in 9 out of 10 patients but recently, using fluorescence microscopy of erythrocytes, no patients with EPP have been missed. All 14 patients in Northern Ireland known to have EPP were recalled and it was found that fluorescence microscopic determination was positive in all cases. We recommend fluorescence microscopy as the screening test of choice for the detection of increased red cell porphyrins.
Atopy in subjects with a history of nickel allergy but negative patch tests.
Various markers of atopy were studied in 20 subjects with a history of nickel allergy but negative patch test reactions, and compared with 2 control groups: 13 subjects with no history of nickel allergy and negative patch tests; 11 subjects with a history of nickel allergy and positive patch tests. No significant difference in the incidence of atopy was detected in the 3 groups.
Nickel allergy in relationship to previous oral and cutaneous nickel contact.
Potential relationships between the development of nickel allergy and previous ear piercing or orthodontic treatment with nickel-containing appliances were studied in 294 patients. We found 77 (31.2%) of 247 patients with pierced ears were allergic to nickel compared to only three (6.4%) patients without pierced ears (p = 0.001), which confirms earlier suggestions that nickel allergy (as assessed by patch testing) is promoted by ear piercing. If orthodontic treatment preceded the event of ear piercing, the frequency of nickel allergy was reduced from 36% to 25%. This supports the view that oral allergenic contacts may induce immunological tolerance.