Acute kidney injury induced by topical hair straightening products: A systematic review

Table 1 Characteristics of the included case reports and case series

Ref.	Study type	Patient’s age/gender	Comorbidities	Clinical features	Serum creatinine (mg/dL)	Renal sonography	Renal biopsy	Treatment	Outcome	Hair straightening method
Abu-Amer et al[20], 2022	Case report	41/F	Hypothyroidism, sleeve gastrectomy	Weakness, nausea, vomiting	3.46	Yes	Yes	Prednisolone 1 mg/kg	Recovered. creatinine 0.9 after one week	Formaldehyde-free product
Bashir and Khater[16], 2023	Case report	40/F	Hypothyroidism	Scalp rash, hypertension, hyperkalemia	3.5	No	Yes	Pulse steroids	Recovered. Creatinine 0.9 at 4-month follow-up	Formaldehyde-free product
Huber et al[15], 2024	Case report	42/F	Healthy	Weakness, nausea, vomiting, flank pain, diarrhea, flank tenderness, hypertension	6.61	Yes	Yes	Conservative management	Recovered. Creatinine 0.87 at 3-month follow-up	Unknown
Mitler et al[18], 2021	Case report	13/F	Healthy	Abdominal pain, nausea, vomiting, oliguria, tachycardia, hypertension, dehydration, abdominal tenderness	3.56	Yes	Yes	Hemodialysis for four consecutive days	Recovered. Creatinine normalized 6-month follow-up	Formaldehyde-free product
Robert et al[41], 2024	Case report incidence 1	26/F	Healthy	Scalp burning sensation, scalp ulcers, vomiting, diarrhea, fever, back pain	2.1	Yes	No	Unknown	Recovered. Serum creatinine returned to normal (0.78) at the last follow-up	Containing 10% glyoxylic acid but no glycolic acid
	Incidence 2	25/F		Scalp burning sensation, scalp ulcers, vomiting, diarrhea, fever, back pain	2.4	Yes	No	Unknown	Recovered. Serum creatinine returned to normal (0.78) at the last follow-up	Formaldehyde-free product (containing 10% glyoxylic acid but no glycolic acid)
	Incidence 3	24/F		Scalp burning sensation, scalp ulcers, vomiting, diarrhea, fever, back pain	1.9	Yes	No	Unknown	Recovered. Serum creatinine returned to normal (0.78) at the last follow-up	Formaldehyde-free product (containing 10% glyoxylic acid but no glycolic acid)
Zergui et al[14], 2025	Case report	25/F		Nausea, vomiting, weakness	3.2	Yes	No	Saline, calcium gluconate, insulin, 25 g glucose, sodium bicarbonate	Recovered. Serum creatinine returned to 1.2 at the two-week follow-up	Formaldehyde-free product (contained glyoxylic acid)
Ahmed et al[17], 2019	Case series of 2 cases case 1	10/F	Healthy	Vomiting, tachycardia, dyspnea, hypertension, scalp rash	13.2	Yes	Yes	Hemodialysis for three consecutive days; 20 mg/kg/dose methylprednisolone for three days followed by oral prednisone (60 mg/m2/day)	Recovered. Discharged with improved RFTs	Formaldehyde-free product
	Case 2	17/F	Healthy	Vomiting, syncope, scalp rash	9.9	Yes	Yes	Hemodialysis for three consecutive days; corticosteroids 40 mg/day	Recovered. Discharged with normal RFTs	Formaldehyde-free product
Bnaya et al[19], 20231	Case series of 26 cases case 1	24/F	Healthy	Abdominal pain, nausea	5.82	No	No	No KRT, no steroids	Recovered	Unknown
	Case 2	22/F	Healthy	Abdominal pain, nausea, vomiting, scalp rash	2.76	No	No	No KRT, no steroids	Recovered	Formaldehyde-free product (containing glycolic acid)
	Case 3	30/F	Nephrolithiasis	Nausea, vomiting, scalp rash, flank pain	4.81	No	No	No KRT, no steroids	Recovered	Formaldehyde-free product (containing glycolic acid)
	Case 4	29/F	Healthy	Nausea, vomiting, scalp rash	2.09	No	No	No KRT, no steroids	Recovered	Unknown
	Case 5	21/F	Epilepsy	Abdominal pain, vomiting, scalp rash, headache	11.83	No	Yes	Steroids	Recovered	Unknown
	Case 6	58/F	Healthy	Nausea, flank pain, syncope	7.54	No	Yes	Steroids	Recovered	Formaldehyde-free product (containing glycolic acid)
	Case 7	14/F	Healthy	Nausea, flank pain, headache	3.8	No	No	No KRT, no steroids	Recovered	Unknown
	Case 8	31/F	Healthy, smoking	Abdominal pain, vomiting, diarrhea	8.14	No	No	Temporary hemodialysis	Recovered	Unknown
	Case 9	29/F	Nephrolithiasis	Vomiting, scalp rash	6.8	No	No	No KRT, no steroids	Recovered	Unknown
	Case 10	52/F	Psoriasis, nephrolithiasis	Abdominal pain, flank pain, nausea, vomiting	3.4	No	No	No KRT, no steroids	Recovered	Unknown
	Case 11	24/F	Healthy	Abdominal pain, nausea, fever	2.17	No	No	No KRT, no steroids	Recovered	Formaldehyde-free product (containing glycolic acid)
	Case 12	33/F	Healthy	Nausea, vomiting, chills	6	No	No	No KRT, no steroids	Recovered	Formaldehyde-free product (containing glycolic acid)
	Case 13	13/F	Healthy	Abdominal pain, nausea, vomiting	3.56	No	Yes	Temporary hemodialysis	Recovered	Unknown
	Case 14	17/F	Psoriasis	Abdominal pain, nausea, vomiting	7.1	No	Yes	Temporary hemodialysis and steroids	Recovered	Formaldehyde-free product (containing glycolic acid)
	Case 15	17.5/F	Healthy	Abdominal pain, nausea, vomiting, fever, scalp rash	2.9	No	No	No KRT, no steroids	Recovered	Formaldehyde-free product (containing glycolic acid)
	Case 16	24/F	Healthy	Abdominal pain, nausea, vomiting, scalp rash	4.2	No	No	No KRT, no steroids	Recovered	Unknown
	Case 17	36/F	Healthy	Nausea, vomiting, scalp rash	6	No	No	No KRT, no steroids	Recovered	Unknown
	Case 18	21/F	Healthy	Abdominal pain, nausea, vomiting	3.2	No	No	No KRT, no steroids	Recovered	Unknown
	Case 19	41/F	Hypothyroidism, sleeve gastrectomy	Nausea, vomiting	3.46	No	Yes	No KRT, no steroids	Recovered	Formaldehyde-free product (containing glycolic acid)
	Case 20	19/F	Healthy	Nausea, flank pain, headache	5.09	No	Yes	Steroids	Recovered	Unknown
	Case 21	44/F	Hypercoagulability state (prothrombin variant)	Vomiting, flank pain	7.8	No	No	No KRT, no steroids	Recovered	Unknown
	Case 22	50/F	Healthy	Nausea, vomiting	7.3	No	No	No KRT, no steroids	Recovered	Unknown
	Case 23	21/F	Healthy	Nausea, vomiting, flank pain, scalp rash	3.68	No	No	No KRT, no steroids	Recovered	Formaldehyde-free product (containing glycolic acid)
	Case 24	28/F	Atopic dermatitis, gastroesophageal reflux disease	Nausea, vomiting, flank pain, scalp rash	2.83	No	No	No KRT, no steroids	Recovered	Formaldehyde-free product (containing glycolic acid)
	Case 25	32/F	Healthy	Abdominal pain, nausea, vomiting	9.03	No	Yes	No KRT, no steroids	Recovered	Formaldehyde-free product (containing glycolic acid)
	Case 26	30/F	Healthy	Flank pain	7.36	No	No	No KRT, no steroids	Recovered	Unknown

¹In the case series of Bnaya et al[19], 2023, analyses of hair-straightening products marketed in Israel revealed varying concentrations of glyoxylic acid (range: 0.56%-17.9%) in some of the products. Ethylene glycol and diethylene glycol were not detected. The concentration of formaldehyde was < 200 ppm in most tested products.

KRT: Kidney replacement therapy; F: Female; RFT: Renal function tests.