Medications are a recognised precipitant of linear IgA disease and should always be considered when a patient presents with the disease. If a drug is suspected, it should be stopped. Vancomycin is the drug most commonly associated with the disease [4, 5]. A wide range of other medications including penicillins, captopril, nonsteroidal anti-inflammatory drugs, cephalosporins [3, 6] and amlodipine [7] have also been reported as causal.

The choice of treatment depends on the severity and extent of the disease and patient factors including co-morbidities.

In patients with mild disease, topical clobetasol propionate may be sufficient to gain control [3, 8]. However, in many patients systemic treatment is required.

Dapsone is considered the first-line systemic therapy [9], and most patients with disease limited to the skin respond well [10]. It is started at low doses of <0.5 mg/kg and increased slowly until blistering and pruritus are controlled [11].

Dapsone produces an oxidant stress on red blood cells, and all patients treated with dapsone will experience a benign haemolysis, manifesting as a fall in haemoglobin of 1–2 g/dL [1] with partial correction from a compensatory reticulocytosis [11]. This is usually well tolerated but may limit use in patients with ischaemic heart disease and anaemia. This effect is of particular importance in patients with G6PD deficiency in whom oxidant stress can lead to a severe haemolytic anaemia. In patient groups with a higher incidence of G6PD deficiency (those from the Mediterranean, Middle East, Africa, Southeast Asia and Oceania), screening should be performed prior to commencing dapsone [8, 12]. In patients found to be G6PD deficient, dapsone and sulphonamides should be avoided [8, 9].

Other common side effects of dapsone include a reversible motor neuropathy, hepatitis, cholestatic jaundice and hypoalbuminaemia. These are dose related and rarely seen at doses less than 200 mg/day [11]. The serious side effects of hepatotoxicity and the dapsone syndrome (lymphadenopathy and hepatitis) and aplastic anaemia usually occur within the first 3 months [11, 12] and necessitate careful monitoring of full blood count, liver function tests and appropriate clinical review [11].

Alternatives to dapsone are the sulphonamides. Sulphapyridine (250 mg–3 g daily) is effective but often poorly tolerated, and the dose may need frequent adjustment [8, 11, 12]. Sulphamethoxypyridazine (250 mg–1.5 g daily) is an alternative and is generally better tolerated [8, 12]. The side effects are similar to dapsone; cutaneous allergic reactions, including Stevens-Johnson syndrome and TEN, hepatitis and agranulocytosis are more common than with dapsone [8]. Dapsone intolerance does not preclude the use of sulphonamides [1] and dapsone and sulphonamides can be used in combination [12].