Ethambutol-induced toxic epidermal necrolysis.

continued. Four to fi ve days later patient again developed generalised body rashes with greater intensity for which she was referred to us. On examination she was febrile, vitals were stable, had erythematous patches over both malar prominences with haemorrhagic crusts present over the lips and anterior nares (Fig. 1), multiple areas of erosions all over the body with thick adherent yellow crusts, some showing whitish scales, hyperpigmentation and thick dystrophic nails (Figs. 2 and 3). Nikolsky sign was positive. Rest of the examination was normal. Patient was diagnosed as a case of toxic epidermal necrolysis however no concrete evidence of tuberculosis was found, either on clinical examination or on investigations. Investigations revealed neutrophilic leukocytosis and cultures were sterile. Antitubercular drugs were discontinued and she was put on intravenous methyl prednisolone (125mg x 6 hourly), antibiotics, silver sulfadiazine cream for local application, anaesthetic gel for mouth ulcers and IV fl uids. The skin lesions of patient improved gradually. After about a month of treatment, antitubercular drugs isoniazid, rifampicin, pyrazinamide and ethambutol were restarted individually and sequentially, staring from low doses and escalating gradually at a regular interval of 3 days to fi nd out the off ending agent. On reinstituting the ethambutol her skin lesions fl ared up. She was discharged on 45th day and is doing well on follow-up and no need to add the ATT was felt. TEN is a rare life threatening disorder characterised by extensive necrolysis and detachment of full thickness epidermis, generally induced by drugs. Separation of the dermo-epidermal junction gives skin the typical “wet dressing” appearance2. ADRs are important because they occur frequently; require discontinuation of medication to prevent serious morbidity and even death. The extent of epidermal sloughing may vary and forms a basis for the classifi cation of an individual case as SJS or TEN. SJS includes cases with less than 10% epidermal detachment, mucosal lesions, and widespread purpuric lesions; SJS / TEN overlap when the epidermal detachment is between 10 and 30%; mucosal lesions, widespread purpuric lesions, and TEN when the epidermal detachment is more than 30%, and mucosal lesions and widespread purpuric lesions are present3. The pathophysiological mechanism of SJS and TEN have not been fully elucidated. The aetiological factors of SJS and TEN are EthambutolInduced Toxic Epidermal Necrolysis