Parrot's sign (19th century), refers to at least two

medical signs Signs and symptoms are diagnostic indications of an illness, injury, or condition. Signs are objective and externally observable; symptoms are a person's reported subjective experiences. A sign for example may be a higher or lower temperature ...

; one relating to a large

skull The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent ...

and another to a

pupil The pupil is a hole located in the center of the iris of the eye that allows light to strike the retina.Cassin, B. and Solomon, S. (1990) ''Dictionary of Eye Terminology''. Gainesville, Florida: Triad Publishing Company. It appears black becau ...

reaction. One Parrot's sign describes the bony growth noted at

autopsy An autopsy (also referred to as post-mortem examination, obduction, necropsy, or autopsia cadaverum) is a surgical procedure that consists of a thorough examination of a corpse by dissection to determine the cause, mode, and manner of deat ...

by and

Jonathan Hutchinson Sir Jonathan Hutchinson (23 July 1828 – 23 June 1913), was an English surgeon, ophthalmologist, dermatologist, venereologist, and pathologist, who notably advocated for circumcision. He founded Haslemere Educational Museum. Life Jonathan H ...

on the skulls of children with

congenital syphilis Congenital syphilis is syphilis that occurs when a mother with untreated syphilis passes the infection to her baby during pregnancy or at childbirth, birth. It may present in the fetus, infant, or later. Clinical features vary and differ between ...

(CS) in the 19th century. Later publications also refer to it as the frontal bossing that presents in the late type CS. Initially thought to be

indicative A realis mood ( abbreviated ) is a grammatical mood which is used principally to indicate that something is a statement of fact; in other words, to express what the speaker considers to be a known state of affairs, as in declarative sentence Dec ...

of congenital syphilis, it was noted to be present in other conditions, particularly

rickets Rickets, scientific nomenclature: rachitis (from Greek , meaning 'in or of the spine'), is a condition that results in weak or soft bones in children and may have either dietary deficiency or genetic causes. Symptoms include bowed legs, stun ...

. Some 19th century textbooks also described the sign as the dilatation of a

when the back of the neck is pinched in some cases of

meningitis Meningitis is acute or chronic inflammation of the protective membranes covering the brain and spinal cord, collectively called the meninges. The most common symptoms are fever, intense headache, vomiting and neck stiffness and occasion ...

Background

Marie Jules Parrot was a French physician in Paris, whose early work concentrated on the

brain The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...

, followed by

tuberculosis Tuberculosis (TB), also known colloquially as the "white death", or historically as consumption, is a contagious disease usually caused by ''Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can al ...

and later

syphilis Syphilis () is a sexually transmitted infection caused by the bacterium ''Treponema pallidum'' subspecies ''pallidum''. The signs and symptoms depend on the stage it presents: primary, secondary, latent syphilis, latent or tertiary. The prim ...

Skull

Parrot's sign, also known as 'Parrot's nodes' and 'Parrot's bosses', refers to the bony growth noted at

by Marie Jules Parrot and

on the skulls of children with

(CS) in the 19th century. Later publications also describe it as the frontal bossing that presents in the late type CS. Initially thought to be

of congenital syphilis, it was noted to be present in other conditions, particularly

. A description of bone findings in CS by Parrot was published in ''The Lancet'' in 1879 following his presentation at a meeting hosted by

and Thomas Barlow in London. In 1883 Barlow referred to the overgrowth of skull bone seen in CS as 'Parrot's swellings' and 'Parrot's bosses'. The nodes were said to be indicative of CS. In Timothy Holmes' and Thomas Pickering 's '' A Treatise on Surgery: Its Principles and Practice'' (1889) it was noted that Parrot's nodes could co-exist with thinning bone in the same skull. The nodes were described in ''

Gray's Anatomy ''Gray's Anatomy'' is a reference book of human anatomy written by Henry Gray, illustrated by Henry Vandyke Carter and first published in London in 1858. It has had multiple revised editions, and the current edition, the 42nd (October 2020 ...

'' (1893) as appearing like

buttocks The buttocks (: buttock) are two rounded portions of the exterior anatomy of most mammals, located on the posterior of the pelvic region. In humans, the buttocks are located between the lower back and the perineum. They are composed of a lay ...

hot cross bun A hot cross bun is a spiced bun, usually containing small pieces of raisins and marked with a cross on the top, traditionally eaten on Good Friday in the United Kingdom, Ireland, Australia, New Zealand, South Africa, Canada, India, Pakistan, M ...

depending on which skull bones were affected. According to D'Arcy Power in 1895, they were first reported by Parrot and Hutchinson, and also found in

, and therefore could not strictly make them indicative of congenital syphilis. In

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and

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'' A Short Practice of Surgery'' (1959), Parrot's nodes were said to consist of patches of periostitis in CS.

Pupil

Parrot's sign was described in some

ophthalmology Ophthalmology (, ) is the branch of medicine that deals with the diagnosis, treatment, and surgery of eye diseases and disorders. An ophthalmologist is a physician who undergoes subspecialty training in medical and surgical eye care. Following a ...

textbooks of the 19th century as the dilatation of a

when the back of the neck is pinched in some cases of

Background

Skull

Pupil

See also

References

Further reading