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Biomedical subjects

D J Gawkrodger

Publications and source records attributed to D J Gawkrodger.

At least 19 recordsLinked to original sources
PubMed1992

Rosacea: a study of clinical patterns, blood flow, and the role of Demodex folliculorum.

BACKGROUND: Rosacea is a common facial eruption that has various clinical presentations. OBJECTIVE: We studied blood flow in lesional skin and explored the role of Demodex folliculorum in patients with rosacea. METHODS: A survey of clinical presentations was made in 108 patients with rosacea. Facial blood flow was studied by laser-Doppler flowmetry. The presence of Demodex was determined by microscopy of skin samples. RESULTS: The sex incidence was equal. The incidence peaked in the fourth and seventh decades of life. Lymphedema was common and was seen in 26 patients. Rhinophyma was present in 15 patients, mostly men. Eleven patients were black, an unexpectedly high number. Laser-Doppler flowmetry showed that lesional blood flow was three to four times that of control subjects. Demodex folliculorum was found in 20 of 25 rosacea patients examined but in only 2 of 20 control subjects. CONCLUSION: The findings indicate that the papillary dermal vasculature is dilated in rosacea. Demodex may be present. These findings give no definitive clue as to the origin of the disease.

Adult↗
PubMed1992

Nickel sensitivity: the influence of ear piercing and atopy.

In a group of 612 consecutive patients undergoing routine patch tests for suspected allergic contact dermatitis, more than four-fifths of the 364 women had had their ears pierced, over half gave a history of cutaneous reactions to metallic jewelery and almost one-third were sensitive to nickel. The increase in the frequency of nickel sensitivity in women with pierced ears compared to those with unpierced ears was highly significant (P less than 0.001). In men, nickel sensitivity was much less frequent; occupational factors were often implicated and few cases were related to ear piercing. Jewelery dermatitis was more frequent in atopic than non-atopic women but atopy did not appear to influence the propensity for developing nickel sensitivity in either sex. Ear piercing seems to induce nickel allergy which may result in lifelong morbidity and difficulty in employment. Jewelery suppliers should be encouraged to provide nickel-free earrings to reduce the frequency of this apparently avoidable problem.

Adult↗
PubMed1991

Quantification of allergic and irritant patch test reactions using laser-Doppler flowmetry and erythema index.

The laser-Doppler blood flow and erythema index were assessed in 16 patch test reactions caused by irritants (1% aq. sodium lauryl sulphate and 1% aq. benzalkonium chloride) and in 13 varied allergic reactions, at 2 or 4 days. Both irritant and allergic responses produced statistically significant increases in laser-Doppler flow index and erythema index compared to control sites (p less than 0.05 or less, using the Wilcoxon rank-sum test). A disproportionately greater increase in erythema index than in laser-Doppler flow was seen in mild irritant reactions, compared to allergic, though the two could not be reliably distinguished by these tests. 2 non-allergic nickel sulphate sites produced an increase in both blood flow and erythema without any clinical change. Petrolatum alone produced no significant change in either measurement. The laser-Doppler flow showed an overall correlation with the erythema index (product moment method; r = 0.55, p less than 0.001), but there was little correlation between these indices and patch test reactivity as judged clinically by conventional scoring. Generally, allergic and irritant patch test reactions could not be differentiated on the basis of laser-Doppler flow or erythema index. However, the disproportionate increase in erythema index over laser-Doppler flow index for mild irritant responses warrants further study in other irritant models.

Allergens↗
PubMed1991

Small intestinal function and dietary status in dermatitis herpetiformis.

Small intestinal morphology and function were assessed in 82 patients with dermatitis herpetiformis, 51 of whom were taking a normal diet and 31 a gluten free diet. Methods used were histopathological evaluation of jejunal mucosal biopsy specimens, quantitation of intraepithelial lymphocytes, cellobiose/mannitol permeability test, tissue disaccharidase values, serum antigliadin antibodies, and formal assessment of dietary gluten content by a dietician. There was no correlation between dietary gluten intake and the degree of enteropathy in the 51 patients taking a normal diet, whereas biopsy specimens were normal in 24 of the 31 patients on a gluten free diet, all previously having been abnormal. Eighteen patients on gluten containing diets had normal jejunal histology and in seven of these all tests of small intestinal morphology and function were entirely normal. Intestinal permeability was abnormal and serum antigliadin antibodies were present in most patients with enteropathy. Studies of acid secretion in seven patients showed that hypochlorhydria or achlorhydria did not lead to abnormal permeability in the absence of enteropathy. This study shows that a combination of objective tests of small intestinal architecture and function will detect abnormalities in most dermatitis herpetiformis patients, including some with histologically normal jejunal biopsy specimens. Nevertheless there is a small group in whom all conventional intestinal investigations are entirely normal.

Adolescent↗
PubMed1990

The discrimination between nickel-sensitive and non-nickel-sensitive subjects by an in vitro lymphocyte transformation test.

A lymphocyte transformation test (LTT) was able to distinguish between nickel-sensitive subjects and non-nickel-sensitive controls. Sixty-one out of 66 (92%) nickel-sensitive subjects had positive stimulation indices in 6- and/or 7-day assays using 5 micrograms/ml of nickel sulphate, whereas none of the 43 controls gave positive results. Stimulation indices were not enhanced by the patch testing of subjects to nickel before performing the LTT. A weak correlation was seen between the results of the LTT and the macroscopic degree of patch-test reactivity. The concentration of nickel sulphate used (5 micrograms/ml) did not have a significant non-specific mitogenic effect.

Adult↗
PubMed1990

Syringoacanthoma: an acrosyringeal tumour.

Syringoacanthoma is a rare benign appendage tumour derived from the intraepidermal portion of the acrosyringium. We report its occurrence in 3 women. In each case the tumour clinically most resembled a seborrhoeic keratosis. Its importance histopathologically lies in the need to differentiate it from conditions such as malignant melanoma, squamous cell carcinoma, intraepidermal carcinoma, Paget's disease and metastasis, which may all show intraepidermal spread.

Adenoma, Sweat Gland↗
PubMed1989

Bullous lichen planus and lichen planus pemphigoides--clinico-pathological comparisons.

Two patients with lichen planus pemphigoides and two with bullous lichen planus were compared. Lichen planus pemphigoides was clinically distinguished by a more generalized lichen planus, more extensive blistering, the need for systemic corticosteroids and by a longer course. The blister of bullous lichen planus was a subepidermal bulla showing degeneration of the epidermal basal layer and other features of lichen planus, whereas in lichen planus pemphigoides the bulla was similar to that of bullous pemphigoid albeit with rather more neutrophils than are usually seen. Direct immunofluorescence was positive in lichen planus pemphigoides and negative in bullous lichen planus. Lichen planus pemphigoides and bullous lichen planus are separate entities: the former is an auto-immune disease precipitated by lichen planus and not related to bullous pemphigoid, the latter is probably not auto-immune but represents the extreme consequence of the lymphoid infiltrate at the dermo-epidermal junction.

Adult↗
PubMed1989

The hapten in contact hypersensitivity to dinitrochlorobenzene: immunoelectron microscopic and immunofluorescent studies.

Six hours after challenge with dinitrochlorobenzene (DNCB) in sensitized volunteers, infrequent cells reacting with both OKT6 (CD 1a) and with an antibody to DNCB were demonstrated in the upper dermis in 3 out of 4 subjects, using a double fluorescence technique. Single marker studies using polyclonal and monoclonal antibodies to DNCB showed cytoplasmic reactivity with peripheral accentuation in keratinocytes throughout the epidermis, most intense in the granular and basal layers, and occasional positive cells in the papillary dermis. Immunoperoxidase electron microscopy using polyclonal and monoclonal antibodies to DNCB demonstrated reactivity on keratinocyte and Langerhans cell membranes, with intracellular deposition of reaction product on mitochondria. Reaction product was present on the external leaflets of Birbeck granules, suggesting that the penetration of DNCB was passive rather than due to an active endocytic process. The immunofluorescent studies suggest that the double-fluorescing upper dermal cells were Langerhans cells but this could not be confirmed by electron microscopy.

Aged↗