Floor-pattern salt-split skin cannot distinguish bullous pemphigoid from epidermolysis bullosa acquisita. Use of toad skin.

BACKGROUND AND DESIGN: Patients with epidermolysis bullosa acquisita (EBA) and bullous pemphigoid (BP) can present with similar clinical features. These antigens have different phylogenetic origins. It was thought that sodium chloride split-skin immunofluorescence could reliably distinguish between BP and EBA. However, it has now been recognized that both diseases can present with a floor pattern fluorescence on salt-split skin. A simple method is required to distinguish these diseases. RESULTS: Serum specimens from two patients presenting with pruritic blisters showing a floor pattern immunofluorescence on salt-split skin were found to have positive fluorescence on toad skin that has the BP and not the EBA antigen. The diagnosis of BP in these patients was confirmed by a prompt response to treatment with systemic steroids. Electron microscopy showed a split at the lamina lucida. CONCLUSIONS: Bullous pemphigoid can present with a floor pattern immunofluorescence on salt-split skin. The use of the skin from invertebrates like the toad may help in distinguishing BP from EBA.

Drug-induced purpura simplex: clinical and histological characteristics.

Purpura simplex (PS) is a chronic condition manifesting as purpura, dermatitis and pigmentation. Histologically it is characterised by extravasation of erythrocytes and perivascular inflammation without fibrinoid necrosis. Most cases of PS are idiopathic. In order to determine if PS can be drug induced, a prospective study of 183 patients with PS was carried out. Of these, 27 patients were confirmed to be drug induced, as the purpura cleared on withdrawal of medications within four months. Lesions of drug-induced PS were significantly more generalised as compared to PS patients without a drug history. No epidermal involvement and an absence of lichenoid infiltrate characterised drug-induced as compared to idiopathic PS. NSAIDs, diuretics, meprobamate and ampicillin were the commonest offenders. We conclude that a drug-induced subgroup of PS exists and can be identified by clinical and histological features. Therefore, a careful drug history and skin biopsy are recommended in all cases of PS.

Pemphigus in remission: value of negative direct immunofluorescence in management.

BACKGROUND: Pemphigus vulgaris is characterized by relapses and remission, and there are currently no sensitive markers to predict remission. OBJECTIVE: Our purpose was to determine if direct immunofluorescence (DIF) performed during clinical remission of pemphigus is useful in management of the disease. METHODS: Twenty-eight patients with pemphigus that was in clinical remission (i.e., patients who were taking low-dose prednisolone [10 mg/day] and had been blister-free for at least 6 months) underwent DIF. Therapy was then discontinued and patients were prospectively followed up for 5 years. RESULTS: Twenty-two patients had negative results and six patients had positive results of DIF. The disease remained in remission in three quarters of the patients with negative results of DIF. Of those who had a relapse, intercellular C3 on DIF and oral lesions on initial presentation were important risk factors, and the relapses in patients with negative results of DIF were mild. The biopsy site was unimportant. All patients with positive results of DIF had major relapses within 3 months of cessation of therapy. CONCLUSION: DIF should be performed before therapy is discontinued. A negative DIF finding is a good indicator of remission in pemphigus.

Oral lichenoid lesions caused by allergy to mercury in amalgam fillings.

Oral lichenoid lesions (OLL) or lichen-planus-like lesions are often idiopathic. Our aim was to determine whether OLL can be caused by allergy to mercury in amalgam fillings, and whether resolution of OLL occurs after replacement of amalgam with other dental fillings. Patients with only OLL (except for 1 case with cutaneous lichen planus) referred for patch testing during 1985-1994 to the Contact and Occupational Dermatitis Clinic of the Skin & Cancer Foundation, Darlinghurst, were reviewed. Patch tests were performed with 1% mercury, 1% ammoniated mercury, 0.1% thimerosal, 0.1% mercuric chloride, 0.05% phenylmercuric nitrate and an amalgam disc, using Finn Chambers occluded for 2 days, 19 patients (17 women and 2 men; age range: 28-72 years) had OLL in close contact with amalgam fillings and showed positive patch test reactions to mercury compounds, 16 out of 19 patients had their amalgam fillings replaced. In 13 patients, the OLL healed. 1 patient had marked improvement. 1 patient had no improvement and developed multiple oral squamous cell carcinoma. In conclusion, OLL can be caused by allergy to mercury in amalgam fillings. Replacement of amalgam with other dental fillings usually results in resolution of OLL and is recommended for cases with positive patch test reactions to mercury compounds.

Pseudoscleroderma secondary to phytomenadione (vitamin K1) injections: Texier's disease.

Cutaneous reactions to vitamin K1 (phytomenadione) are uncommon. They can present as acute eczematous reactions or late reactions that resemble localized scleroderma after vitamin K1 injections. A case is reported here of a patient who developed bilateral sclerodermoid plaques in a cowboy's holster pattern, which persisted for more than 10 years after subcutaneous vitamin K1 injections. Positive intradermal test with vitamin K1 that persisted as an erythematous indurated plaque at the test site for more than 5 months confirmed marked cutaneous hypersensitivity to vitamin K1 in this patient. Serial biopsies of the erythematous plaque at the test site showed transition from spongiotic eczematous features initially to inflammatory morphoea-like histology over a 5 month period. Possible pathogenic mechanisms for phytomenadione-induced pseudoscleroderma are discussed.

Idiopathic hypersensitivity vasculitis: clinicopathologic correlation of 61 cases.

BACKGROUND: Little is known of the course and prognosis of hypersensitivity vasculitis (HV). METHODS: Sixty-one cases of idiopathic HV were biopsied and followed-up for 5 years. RESULTS: There were two predominant patterns of presentation: palpable purpura (PP) and vasculitic ulcers (VU). The former was self-limiting, whereas the prognosis of the latter was poor. Findings on histopathology correlate well in PP patients having acute episodes, whereas in patients with VU there is correlation with duration and recurrence. CONCLUSION: A biopsy of a fresh lesion is recommended to help in determining the outcome.