G.P. Haffenden

Linear IgA disease in adults

A multi‐centre study is described in which thirty‐five adult patients with papillary IgA dermatitis herpetiformis (DH) were compared with forty‐two patients with linear IgA deposits, of whom thirty‐four had homogeneous‐linear (HL) and eight had granular‐linear (GL) IgA deposits.

Immunofluorescent studies in ocular cicatricial pemphigoid.

Twenty nine patients with cicatrizing conjunctivitis were studied; 17 with a clinical diagnosis of cicatricial pemphigoid, five with a clinical diagnosis of pseudopemphigoid caused by long‐term application of topical medication and seven who had a cicatrizing conjunctivitis from other causes. Biopsies from clinically uninvolved bulbar conjunctiva were taken for direct immunofluorescence and blood was taken for indirect immunofluorescence using normal human conjunctiva, oral mucosa and skin as substrates.

Long term follow‐up of dermatitis herpetiformis with and without dietary gluten withdrawal

Seventy‐eight patients with dermatitis herpetiformis have been followed up for periods ranging from 3 to 14 years (mean 7.4). Forty‐two patients were treated with gluten‐free diet (GFD) and thirty‐six took a normal diet (ND). Thirty of the forty‐two (71%) taking the GFD were able to discontinue drugs previously needed to control their rash compared with five (14%) of the thirty‐six patients taking a ND. The mean time taken to reduce drug requirements for patients taking a GFD was 8 months (range 4–30), and for stopping drugs, 29 months (range 6–108). The incidence of macroscopic abnormality of the small intestine decreased from 69 to 15%, and the mean intra‐epithelial lymphocyte count decreased significantly in those patients taking a GFD, whereas there was no significant change in patients taking a ND. The improvement in the skin and intestinal lesions was related to the strictness of the GFD.

Pityriasis lichenoides—an immune complex disease

Circulating immune complexes have been detected in patients with pityriasis lichenoides during disease activity when IgM and C3 have been observed in dermal vessels on direct immunofluorescence of fresh lesions. This implies that pityriasis lichenoides is an immune complex disorder and that deposited complexes play a part in the pathogenesis of the condition. There is a characteristic pattern of immunofluorescence which may be a diagnostic aid.

Evidence that the IgA in patients with linear IgA disease is qualitatively different from that of patients with dermatitis herpetiformis

A previous study using immunofluorescent techniques showed J‐chain to be present in the uninvolved skin of patients with papillary IgA dermatitis herpetiformis (DH) in a distribution that was coextensive with the IgA. This implied that the IgA was dimeric and of mucosal origin. In this study, fifteen patients with papillary IgA deposits, fifteen with homogeneous‐linear (HL) IgA deposits and four patients with granular‐linear (GL) IgA deposits were tested for the presence of in vivo bound J‐chain.

Comparison of immunoglobulin and complement deposition in multiple biopsies from the uninvolved skin in dermatitis herpetiformis

The distribution of immunoglobulins and C3 component of complement (C3) in the skin of twenty‐four patients with dermatitis herpetiformis was studied. Skin biopsies were taken from three sites, the extensor surface of the elbow, the flexor surface of the forearm and from the thigh.

IgA and C3 complement in the uninvolved skin in dermatitis herpetiformis after gluten withdrawal

IgA deposits in the skin in 53 patients with dermatitis herpetiformis (DH) have been studied in relation to treatment. In 19 patients the disorder was controlled by a gluten‐free diet (GFD) alone, in 13 patients by dapsone and GFD and in 18 by dapsone alone. In 3 patients the skin disorder became insignificant and required no treatment. Of the patients taking a GFD alone, six had been clear of skin lesions for 7 years, 5 for 3–5 years, and 8 for periods of 6 months‐3 years. IgA deposits were found in all patients in an initial biopsy and in a second biopsy after treatment for periods varying from I to 7 years. There was no difference in the quantity of IgA, as assessed by the amount of fluorescence, whether patients were controlled with a GFD alone, GFD and dapsone, dapsone alone, or in those in clinical remission. The C3 component of complement was present in the skin in 3 of the 19 patients (16%) controlled by a GFD alone, 6 of the 13 patients (46%) of those controlled by a GFD and dapsone, and in 12 of 18 (66%) of the patients taking dapsone alone, and in one of the patients in clinical remission.

Immunofluorescence study of pityriasis lichenoides

In a study of 27 patients with pityriasis lichenoides IgM and C3 have been observed on direct immunofluorescence of fresh lesions. Other immunoglobulins and complement components were not observed. Immunofluorescence was seen in 31 (72%) of 43 fresh lesions. It occurred in the walls of superficial dermal vessels and along the dermal-epidermal junction. This pattern of immunofluorescence appears to be characteristic of the disease. Uninvolved skin showed the immunofluorescence less frequently and old scaly lesions none. The concept that pityriasis lichenoides is an immune complex disorder is discussed.

The potassium iodide patch test in dermatitis herpetiformis in relation to treatment with a gluten‐free diet and dapsone

The potassium iodide patch test was studied in twenty‐six patients with dermatitis herpetiformis. Histological assessment was found more sensitive than clinical. All of five patients with active disease and not on treatment had a positive test, whereas only two of six patients taking a gluten‐free diet (GFD) and one of eight taking dapsone were positive. In another two patients taking a GFD, but in whom the diet had not been strict, the test was positive. All three patients in remission and both patients with the linear pattern of IgA (but with active disease) were negative. Immunofluorescence studies showed no difference in the presence, quantity, or distribution of immunoglobulin, complement or fibrinogen between the patch test site and uninvolved skin, or in the uninvolved skin between patients with and without active lesions.

Ultrastructural Localization of IgA Deposits in Adult Linear IgA Disease

Two cases of adult linear IgA disease are reported. They demonstrate the two sites of deposition of IgA at an ultrastructural level: sub-basal lamina and lamina lucida. This finding supports the view that there are subgroups of this disease. Clinical presentation and histological appearance of lesional skin are misleading, and the immunofluorescent appearance is unhelpful in predicting the ultrastructural localization of the IgA deposit.