Dapsone

Dapsone (4,4'-diaminodiphenylsulfone, DDS) was synthesized a century ago and continues to be a powerful therapeutic tool in many skin diseases. We have tried to retrieve and present the available knowledge and relevant information on this old but still very useful drug with the hope of encouraging and guiding practicing dermatologists to adapt it for various indications. Our objective is to familiarize the clinician with how this agent works, in what disease states it is effective, how to administer it, what adverse effects may occur, and how to monitor the patient receiving this drug.     

Dapsone

Dapsone and other sulfonamides have been used successfully in the treatment of patients with a variety of blistering skin diseases. The patients most likely to respond to dapsone therapy have a predominantly neutrophilic infiltrate in their skin. Therefore the blistering diseases with the most consistent responses to dapsone therapy include dermatitis herpetiformis and linear IgA disease. Dapsone's precise mechanism of action is unknown. In vitro studies have shown that dapsone can interfere with the production of and response to neutrophil chemoattractants and that it may impair the neutrophils' ability to localize to sites of inflammation and produce toxic oxygen intermediates. The safe use of dapsone requires an understanding of the pharmacology and adverse effects of the drug. Hemolytic anemia and methemoglobinemia are two of the dose-related adverse effects. Agranulocytosis, motor neuropathy, and dapsone hypersensitivity syndrome are some of the severe idiosyncratic effects that can occur in patients treated with dapsone. Dapsone is an effective drug for the management of patients with some blistering disease, especially those with predominant neutrophilic infiltrates in the skin. Careful patient selection and close monitoring of patients during therapy with dapsone are critical elements in the safe and effective use of dapsone for patients with blistering skin diseases.     

氨苯砜在皮肤科的应用

氨苯砜（dapsone, DDS）曾被广泛应用于诸多感染性和炎症性皮肤病的治疗，但随着对其致死性药物不良反应-氨苯砜超敏反应综合征（dapsone hypersensitivity syndrome, DHS）的认识，DDS逐步退出临床，目前仅用于麻风的治疗。随着DHS风险因子HLA-B*13:01的发现和转化应用，DDS的应用前景一片光明。本文从DDS的药代学、药效学和就DDS在皮肤科应用做一综述。     

Dapsone and sulfapyridine

Dapsone and sulfapyridine are structurally related compounds with anti-microbial and anti-inflammatory effects. Dapsone remains the most important drug for leprosy and is useful in the prophylaxis of Pneumocystis pneumonia in patients with HIV disease. The medical treatment of choice for dermatitis herpetiformis is dapsone; and sulfapyridine also can be used for those patients who are intolerant of dapsone. Other neutrophilic disorders also may respond to these drugs. Toxic side effects of both dapsone and sulfapyridine are mediated through the hydroxylamine metabolite. These include hemolysis, methemoglobinemia, and agranulocytosis. Careful monitoring for possible adverse reactions includes frequently performing complete blood counts and regular blood chemistry profile determinations.     

Dapsone syndrome--a case report

A 31-year-old male patient with lepromatous leprosy developed fever, malaise, nausea, anorexia, lymphadenopathy, hepatitis, exfoliative dermatitis and ainhum like lesions while on multidrug therapy comprised of dapsone, clofazimine and rifampicin. The provocation tests confirmed the dapsone to be cause of this event.     

Dapsone dependent nodular panniculitis

A patient recorded to be suffering from tuberculoid leprosy since 1973 and on regular Dapsone monotherapy for about nine years developed asymmetrical, erythematous, subcutaneous, nodular swellings restricted chiefly to the extensor aspects of lower limbs two months after discontinuation of Dapsone therapy. During the course of Dapsone treatment, the patient had developed similar swellings twice previously each time when he stopped the drug for about a month. The swellings disappeared on commencement of Dapsone Treatment. This has been reconfirmed under our supervision. The biopsy of one of the lesions revealed panniculitis with vasculitis. The original diagnosis of leprosy was probably invalid.     

Dapsone treatment of folliculitis decalvans

BACKGROUND: Folliculitis decalvans consists of recurrent patchy painful folliculitis of the scalp causing scarring alopecia. The physiopathology of this condition is still unclear, but is likely a manifestation of chronic neutrophilic bacterial folliculitis. Numerous topical and systemic treatments (corticosteroids, antistaphylococcal antibiotics) have been used with variable results. Based on the dapsone antimicrobial activity and its anti-inflammatory action especially directed to the neutrophil metabolism, we treated two patients with severe folliculitis decalvans with this drug. CASE REPORTS: The patients were treated with dapsone at a daily dose of 75 and 100 mg, respectively for 4 to 6 months. After 1 and 2 months, pustular folliculitis progressively cleared, leaving a residual non inflammatory cicatricial alopecia. When maintaining a dapsone dosage at 25 mg/day no relapse occurred during 3 years and 1 year, respectively. No important adverse effect to dapsone was evidenced. After dapsone withdrawal, a moderate relapse of the disease with pruritus and folliculitis occurred after a few weeks in both cases. The disease relapse rapidly cleared after dapsone reintroduction at a daily dose of 25 mg. COMMENTS: Dapsone at moderate dosage was well tolerated and rapidly effective in treating the two cases of folliculitis decalvans. A long term and low dose (25 mg daily) maintenance treatment avoided disease relapses.     

Dapsone in rosacea fulminans

Rosacea fulminans is a rare disease with female predominance characterized by abrupt onset of pustules, papules, and confluent nodules on the face. The conventional treatment consists of systemic glucocorticoids and isotretinoin. We present the case of a 56-year-old woman with a marked facial papulopustular eruption that had followed an initial period of severe seborrhoea. Conventional treatment produced no clear improvement. Dapsone treatment achieved complete healing in 5 weeks.