A rare case of isoniazid-induced erythroderma

Anti-tubercular therapy (ATT) induced exfoliative dermatitis-A case series

Tuberculosis is a serious contagious disease mainly affecting the lungs and is common in the developing countries. The essential component of all antitubercular regimens include Isoniazid, pyrazinamide as first-line drugs. A serious cutaneous adverse drug reaction namely exfoliative dermatitis (erythroderma) is associated with isoniazid use though uncommon but is common among pyrazinamide users. Here we report 3 cases of tuberculosis patients on antitubercular therapy (ATT) for 8 weeks, came to hospital OP (outpatient) with severe generalized redness and scaling with itching distributed all over the body and trunk. Immediately ATT was discontinued and all the three patients were administered antihistaminic and corticosteroid. The patients recovered within 3 weeks. To confirm ATT induced erythroderma and narrow down the offending agents, sequential rechallenge with ATT was done and again these patients had similar lesions erupt all over the body only with isoniazid and pyrazinamide. Antihistamine, steroids were started and the symptoms resolved and completely recovered within 3 weeks. Prompt withdrawal of the culprit drug along with appropriate medications and supportive measures is necessary for good prognosis. Physicians must be judicious while prescribing ATT especially, isoniazid and pyrazinamide as these can precipitate fatal cutaneous adverse reactions. Strict vigilance may help in early detection of this type ADR and timely management.

Isoniazid causes heart looping disorder in zebrafish embryos by the induction of oxidative stress

Background

The cardiotoxicity of isoniazid on zebrafish embryos and its underlying mechanism is unclear.

Methods

Here, we exposed zebrafish embryos at 4 h post-fertilization to different levels of isoniazid and recorded the morphology and number of malformed and dead embryos under the microscope.

Results

The high concentration of isoniazid group showed more malformed and dead embryos than the low concentration of isoniazid group and control group. The morphology of the heart and its alteration were visualized using transgenic zebrafish (cmlc2: GFP) and confirmed by in situ hybridization. The negative effects of isoniazid on the developing heart were characterized by lower heart rate and more heart looping disorders. Mechanistically, PCR showed decreased expression of heart-specific transcription factors when exposed to isoniazid. Oxidative stress was induced by isoniazid in cardiomyocytes, mediated by decreased activities of catalase and superoxide dismutase, which were rescued by scavengers of reactive oxygen species.

Conclusion

In conclusion, this study demonstrated that isoniazid led to heart looping disturbance by the downregulation of cardiac-specific transcription factors and induction of cardiomyocyte apoptosis.

Lichenoid drug reaction due to anti-tubercular therapy presenting as erythroderma

First-line anti-tubercular therapy (ATT) is very effective in management of tuberculosis and is usually well tolerated. Varied spectrum of cutaneous adverse drug reactions is associated with ATT, of which lichenoid drug eruption (LDR) constitutes approximately 10% of the cases. However, LDR presenting as erythroderma is very rare. Here, we report a case of exfoliative dermatitis secondary to LDR which developed after 5 months of ATT.