Granular parakeratosis in adult female secondary to exposure of benzalkonium chloride laundry rinse



We present a 75 year-old female with a 4 month history of worsening bilateral pruritic erythematous eruption with scaly central desquamation and hyperkeratotic red-brown papules coalescing into patches on axillar, abdomen, buttocks and inner thigh. This set on the background of primary biliary cirrhosis complicated by recurrent hepatocellular carcinoma (HCC) requiring regular imaging with contrast exposure. The eruption was initially treated with antifungal therapy and oral cephalexin with minimal improvement. Histology of the affected skin showed confluent parakeratosis with some compact keratosis, small amount of granular material present within the stratum corneum. As her dermatosis progressively worsened despite, the patient was admitted for urgent dermatological workup to avoid delay of her HCC treatment. Revisiting the history of presenting complaint, the patient revealed that she had recently started using a benzylalkonium chloride (BAC) based laundry rinse aid. The patient was diagnosed with granular parakeratosis secondary to BAC exposure and was prescribed topical methylprednisolone aceponate 0.1% ointment and told to cease using the product and any clothing article which may contain traces of BAC. At her four weeks follow-up there was complete resolution of her eruption and the patient underwent successful microwave ablation of her HCC. Granular parakeratosis is a rare reactive skin condition which is often under-recognised in the clinical setting. Red herrings for diagnostic workup for this patient was the presence of liver disease and active malignancy as well as concomitant contrast exposure, which skewed towards necrolytic migratory erythema and contrast-related reaction as the initial differential diagnosis.


Dr. Cecilia Pham

Austin Health

Cecilia Pham is currently the Dermatology Resident at The Northern Hospital in Victoria and is interested in pursuing a career in Clinical Dermatology. Since graduating from the University of Melbourne Medical School in 2014, she has been employed by Austin Health and is now into her second year of Basic Physicians Training.

Cecilia has also completed a Bachelor of Pharmacy degree from the University of Queensland and has had 5 years of experience as a registered pharmacist prior to become a doctor. Outside of medicine, she is passionate about education, particularly within the migrant and refugee community. Cecilia has had an extensive volunteer history as a tutor and is currently volunteering as an English instructor for asylum seekers living in Melbourne. In her spare time, Cecilia enjoys yoga and meditation as a way to distress and rejuvenate. She is also passionate amateur cook and loves to experiment new cooking recipes on family and friends.