Lichenoid drug reaction to isoniazid presenting as exfoliative dermatitis in a patient with acquired immunodeficiency syndrome

Cutaneous lichenoid drug eruptions: A narrative review evaluating demographics, clinical features and culprit medications

Cutaneous lichenoid drug eruptions (LDE) are adverse drug reactions (ADR) characterized by symmetric, erythematous, violaceous papules reminiscent but rarely fully characteristic of lichen planus (LP). We aimed to analyse the literature describing cases of LDE within the last 20 years to provide additional insight into culprit drugs, typical latency to onset of the eruption, the spectrum of clinical presentations, severity and management. A literature search was conducted in MEDLINE between January 2000 and 27 January 2021. The keywords 'lichenoid drug rash' and 'lichenoid drug eruption' were used. Cases were included if LDE diagnosis was made, and culprit drugs were identified. A total of 323 cases with LDE were identified from 163 published case reports and studies. The mean patient age was 58.5 years (1 month to 92 years), and 135 patients (41.8%) were female. Checkpoint inhibitors (CKI) were the most frequently reported culprit drugs (136 cases; 42.1%), followed by tyrosine kinase inhibitors (TKI) (39 cases; 12.0%) and anti-TNF-α-monoclonal antibodies (13 cases; 4.0%). The latency between initiation of the drug and manifestation was 15.7 weeks (range: 0.1-208 weeks). After discontinuing the culprit drug, the median time to resolution was 14.2 weeks (range: 0.71-416 weeks). One hundred thirty-six patients (42.1%) were treated with topical, and 54 patients (16.7%) with systemic glucocorticoids. Overall, we conclude that, albeit rare, LDE is challenging to diagnose ADR induced by mostly CKI, TKI, and biologics. Treatment modalities resemble that of lichen planus, and the culprit drugs had to be discontinued in only 26%, which is low compared with other types of adverse drug reactions. This is probably due to the low risk of aggravation (e.g. toxic epidermal necrolysis) if the drug is continued and the benefit/risk ratio favouring the drug, as is often the case in cancer therapy.

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.

A Case of Cycloserine-Induced Lichenoid Drug Eruption Supported by the Lymphocyte Transformation Test

Lichenoid drug eruption (LDE) is a rare form of delayed-type drug eruption. Among anti-tuberculosis (Tb) agents, cycloserine (CS) has been reported as a rare cause of LDE. Positive results on the lymphocyte transformation test (LTT) have not been reported in patients with LDE. In the present case, we performed LTT and a patch test, and successfully proved CS as the offending drug in this patient, who had been treated with multiple anti-Tb drugs. These observations suggest that CS should be considered a possible cause of LDE and that LTT can be an option for the diagnosis of LDE.

A rare case of isoniazid-induced erythroderma

Tuberculosis is a common infectious disease in developing countries. Isoniazid is established the first-line antitubercular drug and an essential component of all antitubercular regimens. Erythroderma caused by isoniazid is an uncommon but serious adverse drug reaction. We report here a case of a 63-year-old female patient who presented with generalized redness and scaling with itching after 8 weeks of antitubercular treatment (ATT). ATT was stopped immediately, and antihistaminics were started. The patient improved over a period of 2 weeks. On sequential rechallenge, she developed similar lesions all over the body with isoniazid, hence confirming the diagnosis of isoniazid-induced erythroderma.