Warm weather diseases are caused mainly due to prolonged or intense exposure to hot temperatures. Exposure to such extreme heat can make a person seriously ill. The likelihood of illness also depends on factors such as physical activity, clothing, wind, humidity, working and living conditions, and a person’s age and state of mind. Some common warm weather diseases are insect bites, poison ivy, swimmer’s ear and heatstroke. Physicians treating such diseases need to use the correct ICD-10 codes to report the correct diagnoses. Relying on the services of an established medical billing and coding company can help in accurate and timely claim submission for appropriate reimbursement.

ICD-10-CM codes for Insect Bites

It’s common during summer to see and experience various bites and stings by insects, spiders, snakes, animals and marine life. Most of the time, these bites and stings do not cause serious problems. However, in rare circumstances, certain bites and stings can cause severe illness or even death in people who are sensitive to the venom.

When you are approached by a patient who has been bitten by an insect, first you have to verify venom before you report that bug encounter and finalize your code.

After the verifying check,start your search for codes in the ICD-10-CM Index to Diseases and Injuries, where the index entry for “Bite(s) (animal) (human)” has many subentries based on site, such as ankle, arm (upper), chin and so on. There is a separate subentry for “insect,” but it confirms that site is your best bet by instructing you to “See Bite, by site, superficial, insect.”

If your area is arm in the subentry example, then the ICD 10 codes are:

S40-S49: Injuries to the shoulder and upper arm

  • S41.15 Open bite of upper arm
    • S41.151: Open bite of right upper arm
    • S41.151A: …… initial encounter
    • S41.151D: …… subsequent encounter
    • S41.151S: …… sequel

Coding for a non-venomous insect bite is not the same as coding for a venomous spider bite, which you’ll report using the code

  • T63.3– Toxic effect of venom of spider

ICD 10 coding for a non-venomous insect bite is

  • W57– Bitten or stung by non-venomous insect and other non-venomous arthropods

ICD-10-CM codes for Poison Ivy

A number of people suffer after coming into contact with poisonous plants such as poison ivy, poison sumac and poison oak, every year. The ICD-10-CM code for such contact is:

  • L23.7: Allergic contact dermatitis due to plants, except food

ICD-10-CM L23.7 is grouped within Diagnostic Related Group(s) (MS-DRG v36.0):

  • 606: Minor skin disorders with MCC
  • 607: Minor skin disorders without MCC

In some cases, the dermatitis may spread and cause significant issues like skin infections. Using additional ICD-10-CM codes for the infections or other issues documented may help support reporting a higher-level E/M code or procedure code for the specific encounter. The codes are:

  • L00-L08: Infections of the skin and subcutaneous tissue
  • L10-L14: Bullous disorders
  • L20-L30: Dermatitis and eczema
  • L40-L45: Papulosquamous disorders
  • L49-L54: Urticaria and erythema
  • L55-L59: Radiation-related disorders of the skin and subcutaneous tissue
  • L60-L75: Disorders of skin appendages
  • L76-L76: Intraoperative and postprocedural complications of skin and subcutaneous tissue
  • L80-L99: Other disorders of the skin and subcutaneous tissue

ICD-10-CM codes for Swimmer’s Ear

Another common warm weather disease is swimmer’s ear, also known as Otitis externa or external otitis, which is an inflammation of the outer ear and ear canal. The inflammation can be secondary to dermatitis (eczema) only, with no microbial infection, or it can be caused by active bacterial or fungal infection. In either case, but more often with infection, the ear canal skin swells and may become painful or tender to touch. The codes to document this illness are

  • H60.33: Swimmer’s ear
    • H60.331: Swimmer’s ear, right ear
    • H60.332: Swimmer’s ear, left ear
    • H60.333: Swimmer’s ear, bilateral
    • H60.339: Swimmer’s ear, unspecified ear

ICD-10-CM codes for Heat Stroke

The least common but most severe heat-related illness is heat stroke. The ICD-10-CM index has a long list of subentries under “Heat (effects).” Most of them fall under T67.- Effects of heat and light, though there are a few exceptions. The four-character subcategories under T67.- in ICD-10-CM 2019 are:

  • T67.0– Heatstroke and sunstroke
  • T67.1– Heat syncope
  • T67.2– Heat cramp
  • T67.3– Heat exhaustion, anhydrotic
  • T67.4– Heat exhaustion due to salt depletion
  • T67.5– Heat exhaustion, unspecified
  • T67.6– Heat fatigue, transient
  • T67.7– Heat edema
  • T67.8– Other effects of heat and light
  • T67.9– Effect of heat and light, unspecified.

Currently, T67.0- divides into three codes that differ based only on encounter type (initial, subsequent, sequela). When ICD-10-CM 2020 becomes effective on October 1, 2019, those options will expand to give you these more specific codes:

  • T67.01XA: Heatstroke and sunstroke, initial encounter
  • T67.01XD: Heatstroke and sunstroke, subsequent encounter
  • T67.01XS: Heatstroke and sunstroke, sequel
  • T67.02XA: Exertional heatstroke, initial encounter
  • T67.02XD: Exertional heatstroke, subsequent encounter
  • T67.02XS: Exertional heatstroke, sequel
  • T67.09XA: Other heatstroke and sunstroke, initial encounter
  • T67.09XD: Other heatstroke and sunstroke, subsequent encounter
  • T67.09XS: Other heatstroke and sunstroke, sequela.

According to a note under that subcategory in the ICD-10-CM 2020 tabular list available on the CDC ICD-10-CM site, the Subcategory T67.01- will be appropriate for heat apoplexy, heat pyrexia, siriasis, and thermoplegia. And beyond T67.- codes, the index subentries under “Heat (effects)” that don’t fall under T67.- include these conditions:

  • Burn
    • L55.9: Sunburn, unspecified
  • Dermatitis or eczema
    • L59.0: Erythema ab igne [dermatitis ab igne]
  • Prickly or rash
    • L74.0: Miliaria rubra.

Knowing the highly specific ICD-10 codes related to documenting warm weather diseases such as insect bites, poison ivy, swimmer’s ear and heatstroke is important for healthcare providers. For more efficient and reliable coding, physicians can consider services from outsourced medical billing companies, as experienced coders in such firms will be familiar with all applicable codes and can assign the right ones.