Download MBBS (Bachelor of Medicine and Bachelor of Surgery) 3rd Year (Third Year) Opthalmology Allergic Conjuctivitis Topic Handwritten Notes
? It is the inflammation of conjunctiva due to
allergic or hypersensitivity reactions which
may be immediate (humoral) or delayed
(cellular). The conjunctiva is ten times more
sensitive than the skin to allergens.
TYPES
? Simple al ergic conjunctivitis
Seasonal al ergic conjunctivitis (SAC)
Perennial al ergic conjunctivitis (PAC)
? Vernal keratoconjunctivitis (VKC)
? Atopic keratoconjunctivitis (AKC)
? Giant papil ary conjunctivitis (GPC)
? Phlyctenular keratoconjunctivitis (PKC)
? Contact dermoconjunctivitis (CDC)
VERNAL KERATOCONJUNCTIVITIS (VKC) OR
SPRING CATARRH
? It is a recurrent, bilateral, interstitial, self-limiting,
allergic inflammation of the conjunctiva having a
periodic seasonal incidence
? It is considered a hypersensitivity reaction to some
exogenous allergen, such as grass pollens.
Predisposing factors
? 1. Age and sex. 4-20 years; more common in boys
than girls.
? 2. Season. More common in summer; hence the
name spring catarrh looks a misnomer. Recently it is
being labelled as 'Warm weather conjunctivitis'.
? 3. Climate. More prevalent in tropics, less in
temperate zones and almost non-existent in cold
climate.
PATHOLOGY
? 1. Conjunctival epithelium undergoes hyperplasia
and sends downward projections into the
subepithelial tissue.
? 2. Adenoid layer shows marked cel ular
infiltration by eosinophils, plasma cel s,
lymphocytes and histiocytes.
? 3. Fibrous layer shows proliferation which later
on undergoes hyaline changes.
? 4. Conjunctival vessels also show proliferation,
increased permeability and vasodilation.
SYMPTOMS
? Spring catarrh is characterised by marked
burning and itching sensation which is usually
intolerable and accentuated when patient
comes in a warm humid atmosphere. Itching is
more marked with palpebral form of disease.
Other associated symptoms include: mild
photophobia, lacrimation, stringy (ropy)
discharge and heaviness of lids
Signs
? Signs of vernal keratoconjunctivitis can be
described in fol owing three clinical forms:
? 1. Palpebral form. Usual y upper tarsal
conjunctiva of both eyes is involved. The typical
lesion is characterized by the presence of hard,
flat topped, papil ae arranged in a 'cobble-stone'
or 'pavement stone', fashion .In severe cases,
papil ae may hypertrophy to produce cauliflower
like excrescences of 'giant papil ae'. Conjunctival
changes are associated with white ropy discharge
? 2. Bulbar form. It is characterised by: (i) dusky
red triangular congestion of bulbar
conjunctiva in palpebral area; (ii) gelatinous
thickened accumulation of tissue around the
limbus; and (iii) presence of discrete whitish
raised dots along the limbus (Tranta's spots)
? 3. Mixed form. It shows combined features of
both palpebral and bulbar forms
Palpebral form of vernal keratoconjunctivitis.
Bulbar form of vernal keratoconjunctivitis.
Vernal corneal plaque.
Vernal keratopathy
? 1. Punctate epithelial keratitis
? 2. Ulcerative vernal keratitis (shield ulceration)
? 3. Vernal corneal plaques
? 4. Subepithelial scarring
? 5. Pseudogerontoxon
TREATMENT
? LOCAL THERAPY
? Topical steroids :Medrysone ,fluorometholone
? . Mast cell stabilizers such as sodium
cromoglycate (2%)
? Topical antihistaminics
? Topical antihistaminics
Systemic therapy
? Oral antihistaminics
? Oral steroids for a short duration have been
recommended for advanced, very severe,
nonresponsive cases.
Treatment of large papil ae. Very large (giant) papil ae
can be tackled either by :
? Supratarsal injection of long acting steroid or
? Cryo application
? Surgical excision is recommended for extraordinarily
large papil ae.
PHLYCTENULAR
KERATOCONJUNCTIVITIS
? Phlyctenular keratoconjunctivitis is a
characteristic nodular affection occurring as
an allergic response of the conjunctival and
corneal epithelium to some endogenous
allergens to which they have become
sensitized
? It is believed to be a delayed hypersensitivity
(Type IV-cell mediated) response to
endogenous microbial proteins.
CAUSTAIVE ALLERGENS
? 1. Tuberculous proteins were considered,
previously, as the most common cause.
? 2. Staphylococcus proteins are now thought to
account for most of the cases.
? 3. Other allergens may be proteins of
Moraxella Axenfeld bacillius and certain
parasites (worm infestation)
PATHOLOGY
? 1. Stage of nodule formation
? 2. Stage of ulceration
? 3. Stage of granulation.
? 4. Stage of healing
SYMPTOMS
? in simple phlyctenular conjunctivitis are few,
like mild discomfort in the eye, irritation and
reflex watering. However, usually there is
associated mucopurulent conjunctivitis due to
secondary bacterial infection
SIGNS
? The phlyctenular conjunctivitis can present in
three forms: simple, necrotizing and miliary.
.
? Simple phylctenular conjunctivitis.
It is the most commonly seen variety. It is
characterised by the presence of a typical
pinkish white nodule surrounded by
hyperaemia on the bulbar conjunctiva, usually
near the limbus. Most of the times there is
solitary nodule but at times there may be two
nodules (Fig. 4.25). In a few days the nodule
ulcerates at apex which later on gets
epithelised. Rest of the conjunctiva is normal.
? Necrotizing phlyctenular conjunctivitis is
characterised by the presence of a very large
phlycten with necrosis and ulceration leading
to a severe pustular conjunctivitis.
? Miliary phlyctenular conjunctivitis is
characterised by the presence of multiple
phlyctens which may be arranged haphazardly
or in the form of a ring around the limbus and
may even form a ring ulcer
Phlyctenular keratitis
? Corneal involvement may occur secondarily
from extension of conjunctival phlycten; or
rarely as a primary disease. It may present in
two forms: the 'ulcerative phlyctenular
keratitis' or 'diffuse infiltrative keratitis`
? A. Ulcerative phlyctenular keratitis may occur
in the following three forms:
? Sacrofulous ulcer,Fascicular ulcer,Miliary ulcer
Fascicular corneal ulcer.
Phylctenular conjunctivitis.
? B. Diffuse infiltrative phlyctenular keratitis
may appear in the form of central infiltration
of cornea with characteristic rich
vascularization from the periphery, all around
the limbus. It may be superficial or deep.
? Clinical course is usually self-limiting and
phlycten disappears in 8-10 days leaving no
trace. However, recurrences are very common.
TREATMENT
? 1. Local therapy.
? i. Topical steroids, in the form of eye drops or
ointment (dexamethasone or betamethasone)
produce dramatic effect in phlyctenular
keratoconjunctivitis.
? i . Antibiotic drops and ointment should be added
to take care of the associated secondary infection
(mucopurulent conjunctivitis).
? i i. Atropine (1%) eye ointment should be applied
once daily when cornea is involved
? 2. Specific therapy: Attempts must be made to search
and eradicate the following causative conditions:
? i. Tuberculous infection should be excluded by Xrays
chest, Mantoux test, TLC, DLC and ESR. In case, a
tubercular focus is discovered, antitubercular
treatment should be started to combat the infection.
? i . Septic focus, in the form of tonsil itis, adenoiditis, or
caries teeth, when present should be adequately
treated by systemic antibotics and necessary surgical
measures.
? i i. Parasitic infestation should be ruled out by repeated
stool examination and when discovered should be
adequately treated for complete eradication.
This post was last modified on 11 August 2021