What is a Placoid lesion?

Acute posterior multifocal placoid pigment epitheliopathy (APMPPE) is an acquired, inflammatory eye condition affecting the retina, retinal pigment epithelium (pigmented layer of the retina), and choroid. It usually affects both eyes and is characterized by multiple, yellow-white lesions in the back of the eye.

What is Ampiginous Choroiditis?

Ampiginous choroiditis is a primary inflammatory choriocapillaropathy with characteristics of both acute posterior multifocal placoid pigment epitheliopathy and serpiginous choroiditis.

What is relentless Placoid Chorioretinitis?

Relentless placoid chorioretinitis (RPC) is characterized by retinal lesions similar in clinical and angiographic appearance to acute posterior multifocal pigment placoid epitheliopathy (APMPPE) and serpiginous choroidopathy but differing in its widespread distribution, the numerous lesions typically seen, and the …

What is meant by Placoid?

: of, relating to, or being a scale of dermal origin with an enamel-tipped spine characteristic of the elasmobranchs.

What causes APMPPE?

The exact etiology of APMPPE is unknown, however some believe that it is secondary to a delayed-type hypersensitivity-induced occlusive vasculitis. Gass originally posited that inflammation of the outer retina and RPE causes the APMPPE phenotype.

What are Placoid scales made of?

There are large differences in the development of these spines between different species. Placoid scales are composed of a vascular (supplied with blood) inner core of pulp, a middle layer of dentine and a hard enamel-like outer layer of vitrodentine.

How long does Mewds last?

MEWDS is a self limited disease with excellent visual recovery within 2-10 weeks. However residual symptoms including photopsia may persist for months.

What is APMPPE eye disease?

Acute posterior multifocal placoid pigment epitheliopathy (APMPPE) is a rare eye disorder of unknown (idiopathic) cause. The disorder is characterized by the impairment of central vision in one eye (unilateral) but, within a few days, the second eye may also become affected (bilateral).

What are the 4 types of fish scales?

There are four types of fish scales – placoid, cycloid, ctenoid (pronounced ‘ten-oid’), and ganoid.

Are Placoid scales replaced?

Unlike the scales of bony fishes, placoid scales do not increase in size as the fish grows, instead new scales are added between older scales.

What is the dorsal fin used for?

Dorsal fins. The dorsal fins increase the lateral surface of the body during swimming, and thereby provide stability but at the expense of increasing drag (see also BUOYANCY, LOCOMOTION, AND MOVEMENT IN FISHES | Maneuverability).

What causes placoid lesions in the peripapillary region?

Placoid lesions in SC typically appear in the peripapillary region or macula and spread centrifugally in a serpiginous fashion and new lesions erupt from the edges of old lesions. A serpiginous-like chorioretinitis can be caused by syphilis or tuberculosis .

Are there any benign lesions on the scalp?

Most scalp and skull lesions in children are benign. Lipomas, epidermoid cysts, dermoid cysts, and trichilemmal cysts are the most common diagnoses.

What kind of skin condition causes red patches on scalp?

Cradle cap is seborrheic eczema in infants. Psoriasis is a common inflammatory skin condition. In many cases, it affects the scalp, which develops red, scaly, dry patches. Ringworm, or tinea capitis, is a fungal skin infection that produces ring-like patches.

What causes pimples and scabs on the scalp?

For people who shave their heads, the following may help prevent folliculitis on the scalp: Acne is a skin condition that can cause pimples and other lesions to develop in body areas where there are hair follicles, including the scalp.