Symptoms of scleritis include:

- Redness of the sclera and conjunctiva, sometimes changing to a purple hue

- Severe ocular pain, which may radiate to the temple or jaw. The pain is often described as deep or boring.

- Photophobia and tearing

- Decrease in visual acuity, possibly leading to blindness

The pain of episcleritis is less severe than in scleritis. In hyperemia, there is a visible increase in the blood flow to the sclera (hyperaemia), which accounts for the redness of the eye. Unlike in conjunctivitis, this redness will not move with gentle pressure to the conjunctiva.

Symptoms of episcleritis include mild eye pain, redness, and watery eyes. The pain of episcleritis is typically mild, less severe than in scleritis, and may be tender to palpation.

There are two types of episcleritis: the diffuse type, where the redness involves the entire episclera, and the nodular type, where the redness appears more nodular, involving only a small, well-circumscribed area (sectoral). The diffuse type of episcleritis may be less painful than the nodular type. Sometimes, small nodules are present within the episclera, which move slightly over the sclera with gentle pressure.

Discharge is absent with episcleritis, and vision is unaffected. Patients with episcleritis experience far less photophobia than patients with uveitis. Episcleritis does not cause the presence of cells or flare in the anterior chamber of the eye.

Secondary keratitis or uveitis may occur with scleritis. The most severe complications are associated with necrotizing scleritis.

Episcleritis is a benign, self-limiting inflammatory disease affecting part of the eye called the episclera. The episclera is a thin layer of tissue that lies between the conjunctiva and the connective tissue layer that forms the white of the eye (sclera). Episcleritis is a common condition, and is characterized by the abrupt onset of mild eye pain and redness.

There are two types of episcleritis, nodular and simple. Nodular episcleritis lesions have raised surface. Simple episcleritis lesions are flat. There are two subtypes. In diffuse simple episcleritis, inflammation is generalized. In sectoral simple episcleritis, the inflammation is restricted to one region.

Most cases of episcleritis have no identifiable cause, although a small fraction of cases is associated with various systemic diseases. Often people with episcleritis experience it recurrently. Treatment focuses on decreasing discomfort, and includes lubricating eye drops. More severe cases may be treated with topical corticosteroids or oral anti-inflammatory medications (NSAIDs).

A reduction in visual acuity in a 'red eye' is indicative of serious ocular disease, such as keratitis, iridocyclitis, and glaucoma, and never occurs in simple conjunctivitis without accompanying corneal involvement.

Those with conjunctivitis may report mild irritation or scratchiness, but never extreme pain, which is an indicator of more serious disease such as keratitis, corneal ulceration, iridocyclitis, or acute glaucoma.

Red eye, swelling of conjunctiva and watering of the eyes are symptoms common to all forms of conjunctivitis. However, the pupils should be normally reactive, and the visual acuity normal.

Viral conjunctivitis is often associated with an infection of the upper respiratory tract, a common cold, or a sore throat. Its symptoms include excessive watering and itching. The infection usually begins with one eye, but may spread easily to the other.

Viral conjunctivitis shows a fine, diffuse pinkness of the conjunctiva, which is easily mistaken for the ciliary infection of iris (iritis), but there are usually corroborative signs on microscopy, particularly numerous lymphoid follicles on the tarsal conjunctiva, and sometimes a punctate keratitis.

Late congenital syphilitic oculopathy is a disease of the eye, a manifestation of late congenital syphilis. It can appear as:

- Interstitial keratitis – this commonly appears between ages 6 and 12. Symptoms include lacrimation and photophobia. Pathological vascularization of the cornea cause it to turn pink or salmon colored. 90% of cases affect both eyes.

- Episcleritis or scleritis – nodules appear in or overlying the sclera (white of eye)

- Iritis or iris papules – vascular infiltration of the iris causes rosy color change and yellow/red nodules.

- Chorioretinitis, papillitis, retinal vasculitis – retinal changes can resemble retinitis pigmentosa.

- Exudative retinal detachment

Congenital syphilis is categorized by the age of the child. Early congenital syphilis occurs in children under 2 years old, and late congenital syphilis in children at or greater than 2 years old. Manifestations of late congenital syphilis are similar to those of secondary syphilis and tertiary syphilis in adults.

Neurological causes for photophobia include:

- Autism spectrum disorders

- Chiari malformation

- Occipital Neuralgia

- Dyslexia

- Encephalitis including Myalgic encephalomyelitis aka Chronic fatigue syndrome

- Meningitis

- Trigeminal disturbance causes central sensitization (hence, multiple other associated hypersensitivities. Causes can be bad bite, infected tooth, etc.

- Subarachnoid haemorrhage

- Tumor of the posterior cranial fossa

Causes of photophobia relating directly to the eye itself include:

- Achromatopsia

- Aniridia

- Anticholinergic drugs may cause photophobia by paralyzing the iris sphincter muscle.

- Aphakia (absence of the lens of the eye)

- Blepharitis

- Buphthalmos (abnormally narrow angle between the cornea and iris)

- Cataracts

- Coloboma

- Cone dystrophy

- Congenital abnormalities of the eye

- Viral conjunctivitis ("pink eye")

- Corneal abrasion

- Corneal dystrophy

- Corneal ulcer

- Disruption of the corneal epithelium, such as that caused by a corneal foreign body or keratitis

- Ectopia lentis

- Endophthalmitis

- Eye trauma caused by disease, injury, or infection such as chalazion, episcleritis, glaucoma, keratoconus, or optic nerve hypoplasia

- Hydrophthalmos, or congenital glaucoma

- Iritis

- The drug isotretinoin (Accutane/Roaccutane) has been associated with photophobia

- Optic neuritis

- Pigment dispersion syndrome

- Pupillary dilation (naturally or chemically induced)

- Retinal detachment

- Scarring of the cornea or sclera

- Uveitis

Any potential ocular involvement should be assessed by an ophthalmologist as complications such as episcleritis and uveitis may occur.

Anterior uveitis develops in 40–50% of cases with HZO within 2 weeks of onset of the skin rashes. Typical HZO keratitis at least mild iritis, especially if Hutchinson's sign is positive for the presence of vescicles upon the tip of the nose.

Features:

This non-granulomatous iridocyclitis is associated with:

- Small keratic precipitates

- Mild aqueous flare

- Occasionally haemorrhagic hypopion.

HZO uveitis is associated with complications such as iris atrophy and secondary glaucoma are not uncommon. Complicated cataract may develop in the late stages of the disease.

A limbal nodule is any nodular lesion at the limbus (junction of the cornea and sclera) of the eye.

The differential diagnosis for a limbal nodule can include:

- Pinguecula

- Early Pterygium

- Foreign body / foreign body granuloma

- Phlycten, an inflamed nodule of lymphoid tissue

- Episcleritis

- Scleritis

- Granuloma

- Limbal dermoid, a kind of choristoma (NB: in other organs "dermoid" can refer to a teratoma)

- malignant melanoma

Involvement of the eye is rarely the initial symptom but develops in 60% of persons with RP. The most common forms of ocular involvement are usually mild and often consist of unilateral or bilateral episcleritis and/or scleritis, that is often anterior and could be lingering or relapsing. Scleritis that is necrotizing is found to be exceedingly rare. Less often, conjunctivitis occurs.

There are also other ocular manifestations that occur in persons with RP, these include keratoconjunctivitis sicca, peripheral keratitis (rarely with ulcerations), anterior uveitis, retinal vasculitis, proptosis, lid edema, keratoconus, retinopathy, iridocyclitis and ischemic optic neuritis that can lead to blindness.

Cataract also is reported in relation to either the disease or to glucocorticoid exposure.

The involvement of the peripheral or central nervous system is relatively rare and only occurs in 3% of persons affected with RP, and is sometimes seen in a relation with concomitant vasculitis.

The most common neurological manifestation are palsies of the cranial nerves V and VII. Also hemiplegia, ataxia, myelitis and polyneuropathy have been reported in scientific literature.

Very rare neurological manifestations include aseptic meningitis, meningoencephalitis, stroke, focal or generalized seizures and intracranial aneurysm.

Magnetic Resonance Imaging of the brain shows multifocal areas of enhancement consistent with cerebral vasculitis in some cases.

Initial signs are extremely variable, and diagnosis can be severely delayed due to the nonspecific nature of the symptoms. In general, rhinitis is the first sign in most people.

- Kidney: rapidly progressive glomerulonephritis (75%), leading to chronic kidney failure

- Upper airway, eye and ear disease:

- Nose: pain, stuffiness, nosebleeds, rhinitis, crusting, "saddle-nose" deformity due to a perforated septum

- Ears: conductive hearing loss due to auditory tube dysfunction, sensorineural hearing loss (unclear mechanism)

- Oral cavity: strawberry gingivitis, underlying bone destruction with loosening of teeth, non-specific ulcerations throughout oral mucosa

- Eyes: pseudotumours, scleritis, conjunctivitis, uveitis, episcleritis

- Trachea: subglottal stenosis

- Lungs: pulmonary nodules (referred to as "coin lesions"), infiltrates (often interpreted as pneumonia), cavitary lesions, pulmonary haemorrhage causing haemoptysis, and rarely bronchial stenosis.

- Arthritis: Pain or swelling (60%), often initially diagnosed as rheumatoid arthritis

- Skin: nodules on the elbow, purpura, various others (see "cutaneous vasculitis")

- Nervous system: occasionally sensory neuropathy (10%) and rarely mononeuritis multiplex

- Heart, gastrointestinal tract, brain, other organs: rarely affected.

Granulomatosis with polyangiitis (GPA), formerly known as Wegener's granulomatosis (WG), is a systemic disorder that involves both granulomatosis and . It is a form of vasculitis (inflammation of blood vessels) that affects small- and medium-size vessels in many organs. Damage to the lungs and kidneys can be fatal. Treatment requires long-term immunosuppression.

Granulomatosis with polyangiitis is part of a larger group of vasculitic syndromes called systemic vasculitides or necrotizing vasculopathies, all of which feature an autoimmune attack by an abnormal type of circulating antibody termed ANCAs (antineutrophil cytoplasmic antibodies) against small and medium-size blood vessels. Apart from GPA, this category includes eosinophilic granulomatosis with polyangiitis (EGPA) and microscopic polyangiitis. Although GPA affects small- and medium-size vessels, it is formally classified as one of the small vessel vasculitides in the Chapel Hill system.

Many people with Crohn's disease have symptoms for years before the diagnosis. The usual onset is between 15 and 30 years of age, but can occur at any age. Because of the 'patchy' nature of the gastrointestinal disease and the depth of tissue involvement, initial symptoms can be more subtle than those of ulcerative colitis. People with Crohn's disease experience chronic recurring periods of flare-ups and remission.

Abdominal pain may be the initial symptom of Crohn's disease usually in the lower right area. It is often accompanied by diarrhea, especially in those who have had surgery. The diarrhea may or may not be bloody. The nature of the diarrhea in Crohn's disease depends on the part of the small intestine or colon involved. Ileitis typically results in large-volume, watery feces. Colitis may result in a smaller volume of feces of higher frequency. Fecal consistency may range from solid to watery. In severe cases, an individual may have more than 20 bowel movements per day and may need to awaken at night to defecate. Visible bleeding in the feces is less common in Crohn's disease than in ulcerative colitis, but may be seen in the setting of Crohn's colitis. Bloody bowel movements typically come and go, and may be bright or dark red in color. In the setting of severe Crohn's colitis, bleeding may be copious. Flatulence and bloating may also add to the intestinal discomfort.

Symptoms caused by intestinal stenosis are also common in Crohn's disease. Abdominal pain is often most severe in areas of the bowel with stenoses. Persistent vomiting and nausea may indicate stenosis from small bowel obstruction or disease involving the stomach, pylorus, or duodenum. Although the association is greater in the context of ulcerative colitis, Crohn's disease may also be associated with primary sclerosing cholangitis, a type of inflammation of the bile ducts.

Perianal discomfort may also be prominent in Crohn's disease. Itchiness or pain around the anus may be suggestive of inflammation, fistulization or abscess around the anal area or anal fissure. Perianal skin tags are also common in Crohn's disease and may appear with or without the presence of colorectal polyps. Fecal incontinence may accompany perianal Crohn's disease. At the opposite end of the gastrointestinal tract, the mouth may be affected by recurrent sores (aphthous ulcers). Rarely, the esophagus, and stomach may be involved in Crohn's disease. These can cause symptoms including difficulty swallowing (dysphagia), upper abdominal pain, and vomiting.

Crohn's disease, like many other chronic, inflammatory diseases, can cause a variety of systemic symptoms. Among children, growth failure is common. Many children are first diagnosed with Crohn's disease based on inability to maintain growth. As it may manifest at the time of the growth spurt in puberty, up to 30% of children with Crohn's disease may have retardation of growth. Fever may also be present, though fevers greater than 38.5 °C (101.3 °F) are uncommon unless there is a complication such as an abscess. Among older individuals, Crohn's disease may manifest as weight loss, usually related to decreased food intake, since individuals with intestinal symptoms from Crohn's disease often feel better when they do not eat and might lose their appetite. People with extensive small intestine disease may also have malabsorption of carbohydrates or lipids, which can further exacerbate weight loss.

As ulcerative colitis is believed to have a systemic (i.e., autoimmune) origin, patients may present with comorbidities leading to symptoms and complications outside the colon. The frequency of such extraintestinal manifestations has been reported as anywhere between 6 and 47 percent, and include the following:

- Aphthous ulcer of the mouth

- Ophthalmic

- Iritis or uveitis, which is inflammation of the eye's iris

- Episcleritis

- Musculoskeletal:

- Seronegative arthritis, which can be a large-joint oligoarthritis (affecting one or two joints), or may affect many small joints of the hands and feet

- Ankylosing spondylitis, arthritis of the spine

- Sacroiliitis, arthritis of the lower spine

- Cutaneous (related to the skin):

- Erythema nodosum, which is a panniculitis, or inflammation of subcutaneous tissue involving the lower extremities

- Pyoderma gangrenosum, which is a painful ulcerating lesion involving the skin

- Deep venous thrombosis and pulmonary embolism

- Autoimmune hemolytic anemia

- Clubbing, a deformity of the ends of the fingers.

- Primary sclerosing cholangitis, a distinct disease that causes inflammation of the bile ducts

In addition to the extent of involvement, people may also be characterized by the severity of their disease.

- "Mild disease" correlates with fewer than four stools daily, with or without blood, no systemic signs of toxicity, and a normal erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP). Mild abdominal pain or cramping may occur. Patients may believe they are constipated when in fact they are experiencing tenesmus, which is a constant feeling of the need to empty the bowel accompanied by involuntary straining efforts, pain, and cramping with little or no fecal output. Rectal pain is uncommon.

- "Moderate disease" correlates with more than four stools daily, but with minimal signs of toxicity. Patients may display anemia (not requiring transfusions), moderate abdominal pain, and low grade fever, .

- "Severe disease", correlates with more than six bloody stools a day or observable massive and significant bloody bowel movement, and evidence of toxicity as demonstrated by fever, tachycardia, anemia or an elevated ESR or CRP.

- "Fulminant disease" correlates with more than ten bowel movements daily, continuous bleeding, toxicity, abdominal tenderness and distension, blood transfusion requirement and colonic dilation (expansion). Patients in this category may have inflammation extending beyond just the mucosal layer, causing impaired colonic motility and leading to toxic megacolon. If the serous membrane is involved, a colonic perforation may ensue. Unless treated, the fulminant disease will soon lead to death.