Washing hair with custard apple seeds for lice removal can cause toxic keratitis: Study

India: Hair washing with powdered custard apple seeds is a common practice for the removal of head lice in developing countries. Now, a new study published in the journal Cornea has found that this traditional practice can cause toxic keratitis -- an eye disease characterized by inflammation of clear tissue on cornea.

"Health education about the harmful effect of this traditional practice for head lice infestation will prevent toxic keratitis," write the authors.

Preethika Gandhi, Department of Cornea and Refractive Services, Aravind Eye Hospital, Anna Nagar, Madurai, Tamil Nadu, and colleagues reported the clinical features and outcomes of toxic keratitis after application of powdered custard apple seeds for hair washing for head lice infestation.

For the purpose, the researchers conducted a retrospective review of patients presenting to the Aravind Eye Hospital in India with toxic keratitis and a clear history of crushed custard apple seed application over a 3 year period. 19 patients with the acute disease either unilaterally or bilaterally were identified.

Also Read: Contact lens wearers more prone to Keratitis that can lead to blindness

Key findings of the study include:

• Eighteen females and 1 male with a median age of 14 years [interquartile range (IQR) 12–34 years] presented with severe epiphora, congestion, photophobia, and defective vision (median logMar visual acuity 0.4, IQR 0.2–0.8) after application of custard apple seed powder for hair washing.


• Ten eyes (32.2%) had an epithelial defect (median size 9 mm², IQR 5–12 mm²), and 21 (67.7%) eyes had punctate epithelial erosions.


• All the patients were treated with topical antibiotics, and at 3 days follow-up, all of them had a resolution of symptoms and signs with a median logarithm of the minimum angle of resolution (logMAR) visual acuity of 0.

Also Read: Nonresolving Ulcerative Keratitis successfully managed with ayurvedic medicines: case study

“We hypothesized that toxic keratopathy was due to either toxic or mechanical insult of the crushed custard apple seeds to the corneal epithelium. Patients presented to us in an emergency state, mostly within 24 hours, requiring immediate medical attention indicating the acuteness and the toxic effect of the disease,” the authors said.

“This smooth recovery can be attributed to the fact that there was a clear history, immediate presentation of the patient and prompt management with prophylactic antibiotics,” the authors wrote.

To read the complete study log on to doi: 10.1097/ICO.0000000000001981