Chief Complaint:

Painful wounds on skin for months

HPI:

32-year-old male with past medical history of alcohol use disorder and general anxiety disorder presents with painful skin wounds to the right thigh for approximately four months. He curbed his cravings for EtOH with inhalant use. He uses keyboard duster cans several times a week because his mandated urine drug screens cannot test for the chemicals he is inhaling. He uses anywhere between 4-6 cans per use, directly huffing into his mouth, many times until he loses consciousness. Loss of consciousness is not uncommon when he uses and is usually associated with injury from falls because he becomes uncoordinated during and transiently after use. His last fall was one week ago after using while sitting on a 6ft high wall, he fell off backwards, woke up on the ground in pain to his back and posterior head, did not seek medical attention at that time. Patient is right hand dominant, states that he uses his shirt or a handkerchief as a filter when inhaling. He says these skin lesions were worse in the past, he said he was able to see into his leg at one point and visualized what he thought was muscle.

Pertinent Exam Findings:

Skin: Proximal right lateral thigh with various ulcerated wounds of varying age, depth, and size. Scarring around some lesions with the largest ulceration (6cm diameter) appearing to be most recent, erythematous margins, diffuse areas of necrosis with peeling epidermis. Center of 6cm wound extends beyond the dermis layer into adipose tissue. Wounds cover proximal lateral right lower extremity. No erythematous streaking. Color of the surrounding skin otherwise symmetric to left lower extremity. No other rashes or similar lesions seen on remainder of full skin examination.
Extremity: as above, pulses 2/4 (posterior tibial and dorsalis pedis), no edema localized or increased pressure with palpation of right lower extremity compartments. Full active range of motion in bilateral lower extremities without limitation. Newest wound is tender to palpation, otherwise leg is non-tender.
Neuro: Sensation to fine touch equal in bilateral lower extremity, no sensory deficit.

ED Course:

Reapplied non-adherent gauze dressings for burn.

Did not require or request pain medication, no streaking or obvious cellulitis so he did not receive antibiotics.

Agreed with patient’s plan for self-admission to outpatient rehabilitation facility.

DISCUSSION:

Background:

Incidence of nitrous oxide (N₂O) induced burns is unclear, but the National Survey on Drug Use reported that in the year 2015 alone, 1.8 million people 12 years of age and older abused inhalants. Proportionally the group at greatest risk for abuse is early adolescents between 12 and 17 years old, with more than 1 in 5 children having tried inhalants prior to starting the 8th grade. Unlike other drugs of abuse that can be harder to access, inhalants come in a range of sources and are often household items including cleaners, whipped cream cans, paint, or adhesive. Use can easily be hidden as the inhalant’s effects can last less than a minute and may not initially present with any symptoms of use. Various chemicals including fluorinated hydrocarbons and nitrous oxide are to blame for liver and kidney damage, for triggering dysrhythmias, and even death. Signs of acute intoxication can include dizziness, discoordination, dysarthria or abnormal pitch of voice, hallucinations, delusions, and brief euphoria.

One of the more common skin signs of inhalant abuse includes perioral or intranasal dermatitis. In more severe cases, frostbite injuries have been reported. Inside a can, nitrous oxide has been condensed into a liquid state. The commercial function of whipping, mixing or dusting requires a gas state. Heat from room air converts the liquid to gas via the Joule-Thomson effect and leaves the can feeling cold. This process also leaves the air duster output or even the sprayed surface temporarily frosted. This mechanism contributes to frost bite if the contents are continually expelled for extended periods of time such as when the user loses consciousness as the can may continue to spray towards whatever their arm falls on. Also, these canisters are prone to leaks especially if vigorously shaken or held upside down, which can release the liquid at near freezing temperatures.

Diagnosis:

Diagnosis of inhalant use relies almost exclusively on history. One reason that people may choose inhalants is because its use can be particularly difficult to notice clinically or diagnose with tests. For this reason, there may not be a clear history of inhalant use but if the person has struggled with polysubstance abuse, detailed questioning is useful. There are no highly specific lab tests to determine inhalant. Nitrous oxide inhibits the active form of B12 resulting in dysfunction of DNA, RNA, and myelin synthesis. Vitamin B12 deficiency causes central and peripheral nervous system deficits and macrocytic anemia. Other abnormal lab values that are not specific include elevated liver function tests and creatinine. In patients with cardiorespiratory symptoms, a troponin and ECG is useful because there is a suggested association supported by case studies that myocardial ischemia can be associated with inhalants.

Patterns of frostbite can occur in unusual unilateral patterns as the person can unknowingly continue to release the can’s contents. Figure A below illustrates a similar case study of a 24-year-old male with right hand dominance who was inhaling air duster cans and woke up with severe unilateral burns.

Management in ED:

Acute intoxication from inhalant abuse is unlikely to be the reason for presentation in the ED but symptoms may include seizure, palpitations, chest pain, dizziness, headache, or psychosis. Treatment is supportive care.

For burn management, the patient should be assessed for total body surface area involved as well as complete airway examination. Like any other burns, it is important to monitor circumferential wounds, those causing significant swelling or stricture, those extending beyond partial thickness, or those with signs of cellulitis. Depending on wound age, they can be debrided with cool tap water and soap, debrided of any ruptured bullae or necrosed skin, and covered with non-adherent gauze dressing. Prophylactic antibiotics are not recommended in the absence of clear or suspected cellulitis, likewise, topical antibiotics are not suggested for superficial burns but can be used in partial to full thickness wounds. Silver sulfadiazine has fallen out of favor for suspected slowing of wound healing but hydrocolloid or silver-impregnated dressings as well as honey have shown some efficacy in partial thickness or deeper burns.

Prognosis:

Depending on the duration and frequency of inhalant use, patient outcomes range from healthy enough for discharge to sudden death. More commonly, these patients are discharged after sequelae from acute intoxication resolves with time and supportive treatment. Those with significant burns may be admitted if wounds endanger their airway or constitute a major burn based on total body surface area affected. Increased mortality and morbidity with inhalant use depends heavily on frequency and volume of use.

Clinical Pearls:

• • Recognizing possible inhalant use requires high index of suspicion and relies primarily on history obtained from the patient.
  • Use is most common in males ages 12-17 years old.
  • Patients can range from asymptomatic to requiring resuscitation and there are no specific changes to treatment approach for these presentations with a history of inhalant abuse.
  • If frostbite is present, examine skin and airway fully looking for possible unilateral pattern (consider hand dominance).
  • Chronic use can present like Subacute Combined Immunodeficiency with posterior column loss resulting in ataxia, myelopathy, and more signs of CNS/PNS demyelination.
  • Guardians may require counseling on possible sources of abuse for NO₂ or other aerosol products.
  • There is no current confirmatory test for past inhalant abuse but the following are non-specific indications that can contribute to the history:
    • • Macrocytic anemia.
      • Elevated troponin (in acute setting).
      • Elevated liver function tests.
      • Acute kidney injury.

References:

1. Anderson CE, Loomis GA. Recognition and prevention of inhalant abuse. Am Fam Physician. 2003 Sep 1;68(5):869-74. PMID: 13678134.
2. Cao, S. A., Ray, M., & Klebanov, N. (2020). Air duster inhalant abuse causing non-st elevation myocardial infarction. Cureus. https://doi.org/10.7759/cureus.8402.
3. Foundation for a Drug-Free World. (n.d.). Inhalants statistics – abuse rates by teens & children – Drug-free World. Foundation for a Drug-Free World: Find out the Truth about Drugs. https://www.drugfreeworld.org/drugfacts/inhalants/international-statistics.html.
   
4. Hawash, A., Travers, J. B., & Gokce, S. (2019). Toxic cutaneous responses from inhalant abuse. JAAD Case Reports, 5(1), 31–33. https://doi.org/10.1016/j.jdcr.2018.10.009
5. Kurtzman, T. L., Otsuka, K. N., & Wahl, R. A. (2001). Inhalant abuse. Journal of Adolescent Health, 28(3), 170–180. https://doi.org/10.1016/s1054-139x(00)00159-2
6. NIDA. 2020, April 16. Inhalants DrugFacts. Retrieved from https://www.drugabuse.gov/publications/drugfacts/inhalants on 2021, August 6.
7. NOAA (Ed.). (n.d.). Nitrous Oxide Chemical Data Sheet. NOAA Cameo Chemical. https://cameochemicals.noaa.gov/chemical/4093.

Authors

Aaron Wolfe,DO,FACEP, Director of Education for Emergency Medical Minute and Clinical Associate Faculty for Rocky Vista University College of Osteopathic Medicine

Josh Bridge, OMS IV