Title : Beyond the expected: Uncommon dermatologic reactions to widely used drugs- clinical lessons from five cases
Abstract:
Background: While modern therapies have revolutionized patient care, their expanding use is also unveiling a spectrum of rare and unexpected cutaneous side effects. These unique dermatologic manifestations present a growing diagnostic challenge for dermatologists. We present a series of five rare and challenging cases of drug-induced dermatoses, highlighting the critical importance of a high index of suspicion for practitioners.
Case Series: A 62-year male, k/c/o Ca Oesophagus, received 9 weekly sessions of cisplatin, paclitaxel and 5-FU chemotherapy. 8 days after the last session of chemotherapy, he developed multiple palpable non blanchable purpuras over bilateral lower limbs. Platelets were normal; ANA and ANCA were negative. Histopathology confirmed the diagnosis of leukocytoclastic vasculitis. Patient was managed conservatively with high potency topical steroids. Temporal relation, response, and literature suggested a diagnosis of Cisplatin induced Vasculitis. Cisplatin was continued under monitoring since the reaction was mild and localized.
A 50-year female, k/c/o Ca Breast, received 16 cycles of Palbociclib, and presented with multiple violaceous scaly plaques over buttocks and lower limbs. Differentials were Lichenoid drug eruption and Drug Induced Subacute Lupus. ANA was negative. Histopathology was confirmative of Lichenoid drug eruption. Oral steroids were given in tapering doses over 2 weeks. Being a mild reaction, Palbociclib was continued under close monitoring, with complete resolution of lesions.
A 35-year male, k/c/o Borderline Hansen disease, was started on Amitriptyline for neuropathic pain. 5 days after starting the drug, he presented with painful fluid filled lesions over body. Erosions were present in oral mucosa. Clinical examination and biopsy confirmed diagnosis of Bullous fixed drug eruption. Drug was withdrawn and oral steroids were prescribed leading to a gradual resolution of lesions. To the best of our knowledge, amitriptyline induced bullous FDE has not been described yet in the literature.
A 52-year female, k/c/o breast cancer, received 6 cycles of Pemetrexed, presented to us with reticular net like pigmentation over face. A diagnosis of Pemetrexed induced reticular pigmentation was made. The patient was counselled about the benign nature of the pigmentation and continued pemetrexed without interruption. Only 1 case has been reported in literature.
A 60-year male, k/c/o Glioblastoma, on Temozolomide, presented to us with multiple hyperpigmented scaly plaques on sun exposed areas. These lesions developed 2-3 weeks after cessation of radiotherapy. The rash extended beyond the irradiated field and was strictly photo distributed thus ruling out Radiation Recall dermatitis. The bilateral, sun-exposed distribution suggested diagnosis of Temozolomide induced photosensitivity. He was managed with topical steroids and photoprotection. Only 2 reports in literature describe this reaction.
Conclusion: Our series highlights the dermatologist's critical role in recognizing these unique rare cutaneous drug reactions. By identifying them early and managing them appropriately, none of the patients had to discontinue essential cancer therapy. Thus, vigilance in dermatology is not only diagnostic, it is therapeutic.
