Oral drug provocation test to generate a list of safe drugs: Experience with 100 patients.

Background: Following a drug eruption, patients and their doctors need to know which drugs can be safely administered for subsequent illnesses. Currently available laboratory tests are unable to answer this question in a clinically meaningful manner. Aims: To describe our use of oral provocation tests to provide a list of safe drugs to patients. Methods: We studied the records of 100 patients who underwent oral provocation testing in our department between 2003 and 2009. All patients were admitted to hospital and drugs were administered under supervision, one drug per day. A dermatologist evaluated all symptoms and signs that developed following drug intake. Results: Sixty nine women and 31 men underwent provocation testing. There were 96 reactions in 61 patients, of which 44 reactions in 34 patients were judged to be true reactions. All reactions could be controlled, with treatment or spontaneously. A list of safe drugs was provided to the patient along with written instructions to avoid any drug(s) that had produced a reaction. Conclusions: Oral provocation tests are safe and effective in providing patients with a list of drugs they can take safely. These tests should preferably be undertaken after admitting the patient to hospital.

Patient-reported multiple drug reactions: Clinical profile and results of challenge testing.

Background: Some patients report hypersensitivity reactions to many drugs making it difficult to prescribe medications when they fall ill. Aim: To describe the clinical profile of multiple drug hypersensitivity and the results of challenge testing in a large teaching hospital.Methods: We performed a five-year retrospective review of the records of patients who complained of reactions to two or more unrelated drugs and avoided medication because of a fear of developing reactions. Oral challenge testing was carried out in hospital with drugs suspected by the patient to cause reactions and/or commonly prescribed medications. A positive reaction was diagnosed when symptoms and signs resembled previously experienced episodes and there was no such reaction with placebo. Results: Twenty three patients (aged 14-65 years; 19 females) underwent challenge testing. Their complaints had been present for 1-30 years, with 2-40 drug reaction episodes reported. Antibiotics and non-steroidal anti-inflammatory drugs (NSAIDs) were most commonly implicated, and urticaria/angioedema were the most often reported manifestations. The patients underwent 3-27 challenges with 1-24 drugs. Three had positive challenge reactions with various NSAIDs, 13 developed symptoms and signs that were judged not to be true reactions, and 7 had no reactions. None of our patients qualified for a diagnosis of true multiple drug hypersensitivity. Conclusion: Patients who believe they are allergic to multiple, pharmacologically unrelated drugs are usually mistaken. Challenge testing is a reliable way of demonstrating this and providing patients with a list of safe drugs.

A modified two-step treatment for actinomycetoma.

BACKGROUND: Combination antibiotic regimens are effective in the treatment of actinomycetoma but many treatment schedules require supervised parenteral therapy for prolonged periods. We describe a schedule that includes parenteral medication in an initial, short phase followed by a longer phase of oral medication. METHODS: Sixteen patients with clinically diagnosed mycetoma, who did not show any evidence of a fungal etiology, were treated presumptively for actinomycetoma. Evidence of actinomycotic infection was found on microscopy of granules / discharge and / or histopathological examination in eight (50%) patients. The treatment consisted of an intensive phase (Step 1) with gentamicin, 80 mg twice daily, intravenously and cotrimoxazole, 320/1600 mg twice daily orally for four weeks. This was followed by a maintenance phase with cotrimoxazole and doxycycline, 100 mg twice daily till all sinuses healed completely. The treatment was continued for 5-6 months. RESULTS: Treatment response was assessed monthly. At the end of the intensive phase, there was a significant improvement in all 16 patients. Nine patients who continued the maintenance phase of the regimen had complete healing of sinuses with marked reductions in swelling and induration in 2.4 +/- 1.7 months. Maintenance treatment was continued for a mean of 9.1 +/- 4.3 months in these patients. Six patients have remained free of disease activity during a follow-up period of 11.1 +/- 4.2 months after treatment was stopped. Two patients developed leucopenia and thrombocytopenia necessitating withdrawal of cotrimoxazole. CONCLUSION: This regimen was effective in treating actinomycetoma. The short duration of the phase requiring parenteral therapy makes it convenient to administer.

Bullous mastocytosis treated with oral betamethasone therapy.

Bullous mastocytosis is a very rare variant of cutaneous mastocytosis. The condition is characterized by a diffuse infiltration of the skin by mast cells manifesting as yellowish, thickened doughy skin with appearance of large blisters. The authors report herewith a 7-month-old female infant with history of recurrent episodes of vesiculobullous lesions on the face, trunk and the extremities and excessive tendency to rub and scratch the skin for 3 months. She also had recurrent episodes of facial flushing. On cutaneous examination there were multiple flaccid bullae, urticarial wheals and crusted erosions on her scalp, face, neck, trunk and extremities. She had generalised yellowish thick and rough skin, giving doughy feel and 'peau d' orange' appearance of the skin at places. Systemic examination was within normal limits. Skin biopsy from a lesion showed subepidermal bulla and an upper dermal inflammatory infiltrate comprising of lymphocytes and many mast cells. Toluidine blue staining of the cells showed presence of metachromatic granules in these cells. A diagnosis of bullous mastocytosis was made and the patient was treated with oral antihistamines to which there was no satisfactory response. Betamethasone in a dose of 0.1 mg/kg/day given orally caused complete remission of the disease in 4 weeks. The drug was gradually tapered and stopped over the next 6 weeks. There were no side effects of the therapy.