Mnemonic Monday: PERCH on a “Peak” – Picornavirus

By Molly Lewis

Viruses… not only can they literally make you sick to your stomach from gastroenteritis, but trying to remember their classifications can cause significant nausea as well!

The solution? No, it’s not oral rehydration therapy or ondansetron – try a mnemonic!

One of my favorites:

– for the picornaviruses:

PERCH on a Peak

– “peak” ~ pico = Picornaviruses

Perch on a Peak

P = Poliovirus
E = Enteroviruses
R = Rhinoviruses
C = Coxsackie viruses
H = HAV – Hepatitis A virus


– polio (flaccid (lower motor neuron) ascending (starts with distal muscles and moves proximally) paralysis)


– aseptic (viral) meningitis


– common cold (especially in fall and early winter, vs Coronavirus = later winter and spring)

Coxsackie viruses

– type A = hand, foot, mouth disease

– type B = herpangina; myocarditis

HAV – Hepatitis A virus

– hepatitis (known for outbreaks in day care centers, in which the kids get just viral gastroenteritis symptoms, but the adults get jaundice)


– picoRNAviruses = RNA viruses

– pico = “small amount” in Spanish, and these viruses are small RNA viruses!

Picornaviruses are naked single stranded RNA (ssRNA). Since they are naked (without a membrane envelope), they can survive stomach acid and are therefore spread via fecal-oral transmission.


– Technically, the E in the mnemonic should stand for Echovirus (causes aseptic meningitis), since the viruses in the PERC part of the mnemonic are all in the Enterovirus genus of the Picornavirus species, but I’ve found in practice and on tests that this version of the mnemonic works well!).

– There is a significant amount of cross-over in the diseases each virus causes (for example, most of these viruses are known for causing aseptic meningitis (except with Rhinovirus and HAV), enterovirus 71 can cause Hand, foot, mouth disease, and polio can cause aseptic meningitis without paralysis), but I listed the classic (AKA- on the USMLE) associations here.


Mnemonic: First Aid for the USMLE Step 1, 2019, p. 167-168

virus info:



4 thoughts on “Mnemonic Monday: PERCH on a “Peak” – Picornavirus”

  1. Thank you Molly for this useful “Mnemonic Monday“ , especially for the bonus and side notes. I totally agree with.

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