Primary Care Coding Alert

Some common medical conditions seem to always spread like wildfire at the start of the school year, and one of those conditions is conjunctivitis. This highly transmittible eye infection is commonly seen in primary care, but that doesn’t mean it’s a cinch to code. There are several important details you need to see in the documentation to properly code the diagnosis.

Here’s a guide to help you code correctly every time.

Condition refresh: Conjunctivitis is characterized by redness and inflammation of the transparent membrane (conjunctiva) that covers the front surface of the eyeball and lines the inner part of the eyelids.

Check for These Details in the Notes

Conjunctivitis is often a common and self-limited problem that requires little treatment or diagnostic testing. Busy providers may therefore not fill the encounter notes with many of the details you’ll need to code to the highest specificity. Query the provider if any of the following information is missing:

Viral, bacterial, or allergic: Conjunctivitis can be infectious or noninfectious. Infectious forms of the condition are either viral or bacterial. Allergic forms are noninfectious. The source of the infection determines which code set to use. Bacterial and allergic conjunctivitis can be found in Chapter 7: Diseases of the Eye and Adnexa (H00-H59). Viral conjunctivitis codes are in ICD-10 Chapter 1: Certain Infectious and Parasitic Diseases (A00-B99).

Follicular or papillary: You also need to look for details in the notes to see how the irritation presents. Follicular conjunctivitis is usually caused by a virus or bacteria, and looks like small, dome-shaped nodules in the eye. An allergic immune response or a foreign body creates papillae on the surface of the eyelid, classifying it as papillary conjunctivitis. You never want to assume viral, bacterial, or allergic conjunctivitis based on the words “nodules” and “papillae,” so double check with the provider if there is any confusion or discrepant information.

Acute or chronic: Acute conjunctivitis generally lasts one to two weeks, whereas chronic lasts more than four weeks. But be careful. Whether the patient’s condition is acute or chronic is necessary information, but like with all ICD-10 codes, that designation is something that needs to be specifically documented by the provider. As a coder, you cannot extrapolate and assign any condition as acute or chronic based on how long the patient has experienced symptoms.

Which eye is affected: The codes for bacterial and allergic conjunctivitis take a 6th character to account for laterality, which is reported as 1 for the right eye, 2 for the left eye, 3 for both eyes, and 9 for unspecified side. If this information is missing, it’s likely the primary care practitioner (PCP) unintentionally left it off the patient record. The exam would clearly show which eye is affected. It’s always best to ask rather than assign the 9 as the sixth character.

Rely on B30.- for Viral Conjunctivitis

For viral cases, turn to ICD-10 Chapter 1: Certain Infectious and Parasitic Diseases (A00-B99) for proper coding:

• B30.0 (Keratoconjunctivitis due to adenovirus)
• B30.1 (Conjunctivitis due to adenovirus)
• B30.2 (Viral pharyngoconjunctivitis)
• B30.3 (Acute epidemic hemorrhagic conjunctivitis (enteroviral))
• B30.8 (Other viral conjunctivitis)
• B30.9 (Viral conjunctivitis, unspecified)

“Viral conjunctivitis is often associated with an upper respiratory infection and other generalized systematic symptoms such as a sore throat, fever, and headache,” according to Sharanjit Kaur, DO, family medicine physician in Lake Success, New York and lead author of the 2019 Osteopathic Family Physician article “Primary Care Approach to Eye Conditions (www. acofp.org/ACOFPIMIS/Acofporg/PDFs/OFP/Articles/2019_MarApr/2019_MarApr_PrimaryApptoEyeCond.pdf). For example, B30.0 and B30.1 are caused by adenoviruses. More specifically, infections caused by adenovirus serotypes 8, 19, and 37 are coded to B30.0 (Keratoconjunctivitis due to adenovirus), while infections caused by adenovirus serotypes 3, 4, and 7 are coded to B30.2 (Viral pharyngoconjunctivitis). All other adenoviral conjunctivitis conditions are coded to B30.1 (Conjunctivitis due to adenovirus), whereas infections caused by coxsackievirus A24 and enterovirus 70 are coded to B30.3 (Acute epidemic hemorrhagic conjunctivitis (enteroviral)).

Turn to H10.- for Bacterial and Allergic

The H10.- codes (Conjunctivitis), such as the following, describe forms of bacterial and allergic conjunctivitis. Some of the codes require a 6th character:

• H10.01- (Acute follicular conjunctivitis)
• H10.02- (Other mucopurulent conjunctivitis)
• H10.1- (Acute atopic conjunctivitis); which includes acute papillary conjunctivitis
• H10.2- (Other acute conjunctivitis)
• H10.3- (Unspecified acute conjunctivitis)
• H10.4- (Chronic conjunctivitis)
• H10.5- (Blepharoconjunctivitis)
• H10.8- (Other conjunctivitis)
• H10.9 (Unspecified conjunctivitis)

The H10.- codes rely on laterality for accurate coding. For example, if you were to report the form PCPs see most often (what’s commonly known as pink eye) and it presented in both eyes, you’d report H10.013 (Acute follicular conjunctivitis, bilateral). If excessive discharge is documented, the physician may diagnose mucopurulent conjunctivitis. That would code to H10.023 (Other mucopurulent conjunctivitis, bilateral), depending on the provider’s documentation.

While bacterial conjunctivitis is commonly referred to as pink eye, allergic conjunctivitis is commonly referred to as red eye. The allergic form is commonly coded to H10.1-, though chronic allergic conjunctivitis can be coded to H10.44 (Vernal conjunctivitis) if the patient is allergic to airborne allergens such as pollen or pet dander, or even H10.45 (Other chronic allergic conjunctivitis).

Coding alert: “One diagnosis to keep an eye out for is blepharoconjunctivitis. This is different than standard conjunctivitis, as it occurs when bacteria cause irritation and inflammation to the eyelid then spreads to the conjunctiva,” advises Marco Unzueta, BSHIM, CPC, CCS, CIC, CDEO, CDEI, AAPC Approved Instructor, Medical Coding Supervisor at El Paso Children’s Hospital in El Paso, Texas. This condition codes to H10.5- (Blepharoconjunctivitis).

Pediatric coding alert: Like many conditions, there are often different codes for neonates. For example, there is a form of bacterial conjunctivitis caused by the gonococcus bacterium, which is coded as P39.1 (Neonatal conjunctivitis and dacryocystitis).