Hair tourniquet syndrome is a rare clinical phenomenon that involves hair, thread, or similar material becoming so tightly wrapped around an appendage that it results in pain, injury, and, sometimes, loss of the appendage.
Essentially, any appendage may be involved, including a toe, wrist, penis, scrotum, tongue, uvula, vaginal labium, ear lobe, umbilicus, or nipple.
In a meta-analysis review of 210 cases of hair-thread tourniquet syndrome, 44.2% involved the penis, 40.4% the toes, 8.6% fingers, and another 6.8% represented other sites.
Human hair is extremely thin and, hence, easily overlooked, especially when a patient presents with a foreign body reaction and local swelling.
Once constricted over an appendage, reepithelialization may occur if the offending fiber is not removed in a timely fashion. This may further obscure the hair or thread below an overlying skin bridge, making recognition more difficult.
Hair has high tensile strength and the ability to stretch when wet and contract or tighten as it dries.
The wrapping of the offending fiber or hair around a digit is thought to be caused by repetitive movement of the appendage in a confined area, such as hands in mittens or feet in pajamas.
The tissue injury from constricting bands may be caused by ischemic compression of blood vessels and the direct cutting action of the tourniquet.
In addition to soft-tissue damage, this mechanism is even capable of disrupting bone.
Complications such as constrictive scarring, flexion deformity, and even urocutaneous fistulae may affect healing post release.
Most cases of hair wrapping occur in young children. The most often observed age range of reported cases of finger wrapping is in the first days of life up to 19 months, and penile involvement is 4 months to 6 years.
Labial and clitoral wrapping have been described in an older age group (age 7-13 years).
Case reports have documented 80- and 84-year-old men with involved extremities.
Hair tourniquet syndrome can be observed across all ages. The younger age group, especially infants younger than 4 months, is thought to be more at risk because 90% of mothers experience excessive postpartum hair loss, called telogen effluvium.
Most cases of hair tourniquet syndrome are deemed accidental, but intentional cases consistent with child abuse have been cited in the literature.
Although the affected patient can present in several ways, the classic presentation is that of the inconsolable infant. The diagnosis can be made after identification of a swollen and painful appendage with sharp circumferential demarcation from normal tissue proximally. Hair tourniquet syndrome confers an inherent risk of loss of function and autoamputation. However, it is easily treatable and long-term effects are largely preventable with prompt diagnosis. Clinicians should maintain a high index of suspicion when confronted with such presentations.