S90.423 Blister (nonthermal), unspecified great toe

Name of the Condition

• Blister (nonthermal), unspecified great toe (ICD-10 code: S90.423)

Summary

A blister (nonthermal) of the unspecified great toe is a localized collection of fluid beneath the skin, typically resulting from friction or minor trauma. This condition involves the outer layers of the great toe and may cause discomfort or pain, depending on the size and location of the blister. It is not caused by heat-related injuries and is generally superficial.

Causes

Direct friction from ill-fitting footwear or repetitive rubbing. Minor trauma, such as stubbing the toe or impact with a hard object. Prolonged pressure or irritation from tight socks or shoes.

Risk Factors

• Wearing tight or poorly fitting shoes or socks.
• Engaging in activities that increase toe friction (e.g., sports, hiking).
• Reduced sensation in the feet due to conditions like diabetes or neuropathy.

Symptoms

• Fluid-filled sac on the great toe, often clear or slightly yellow.
• Pain, tenderness, or burning sensation at the site.
• Redness or swelling around the blister.

Diagnosis

Physical examination of the great toe to assess the blister's size, location, and surrounding skin. Review of the patient's history to identify potential causes, such as recent footwear changes or activities.

Treatment Options

• Keeping the blister clean and dry to prevent infection.
• Applying protective dressings or moleskin to reduce friction.
• Avoiding popping the blister to allow natural healing.

Prognosis and Follow-Up

Most blisters resolve within a few days with proper care. Follow-up may be recommended if symptoms worsen, signs of infection develop, or the blister does not heal as expected.

Complications

• Infection, particularly if the blister is popped or becomes contaminated.
• Delayed healing due to persistent friction or pressure.

Lifestyle & Prevention

• Wear properly fitting shoes and socks to reduce friction.
• Use protective padding or moleskin on areas prone to blisters.
• Avoid activities that cause repetitive rubbing until the blister heals.

When to Seek Professional Help

Seek medical attention if the blister shows signs of infection (e.g., pus, increased redness, warmth), if pain is severe, or if the blister does not improve with home care.

Tips for Medical Coders

Document the specific toe affected (unspecified great toe) and confirm the blister is nonthermal. Ensure clinical notes support the diagnosis and exclude other causes of blistering.