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Photosensitive disorders
and Urticaria
Sunlight and Skin

Major source of UV and visible radiation
interacting with human skin.

UV radiation : UVC: 200-290 nm
UVB: 290-320 nm
UVA: 320-400 nm

Visible radiation: 400-760 nm

Infrared radiation:760 -100,000 nm

Normal effects of sun exposure on skin:
Sunburn, Tanning, Photoaging, Vitamin D
synthesis.
Skin Phototypes(Fitz Patrick Classification)

I - always burns, never tans

II - always burns, minimally tans

III - burns moderately, gradually tans

IV - burns minimal, always tans

V - burns rarely , severely tans

VI - deeply pigmented.
Indian skin phototypes: Type IV-VI
Classification of Photosensitive disorders

Genodermatoses
◦ Xeroderma pigmentosum, Bloom’s syndrome,
Cockayne syndrome

Idiopathic
◦ Polymorphic light eruptions, Actinic prurigo,
solar urticaria

Phototoxic and photoallergic reactions
◦ Reactions induced by topical/systemic drugs,
chemicals or contactants
Contd…
Classification of Photosensitive disorders

Metabolic
◦ Porphyria, Pellagra

Tumours
◦ Basal cell ca, Squamous cell ca, Melanoma,
Actinic keratoses.

Diseases aggravated by sun exposure
◦ Lupus Erythematosus, Rosacea,
Dermatomyositis, Acne, Psoriasis, Pemphigus,
Atopic dermatitis, Airborne Contact dermatitis
Polymorphous light eruption (PMLE)

Most common photodermatoses

Idiopathic, probably immunological

Younger age, Females

Recurrent pruritic lesions on photo exposed
areas within minutes to hours after sun
exposure.

Clinical patterns:
◦ Macular, papular,papulovesicles,
plaque,lichen-nitidus like lesions.
Polymorphous light eruption (PMLE)

Differential Diagnosis:
◦ Prurigo
◦ Erythema multiforme
◦ Lichen Simplex chronicus
◦ Atopic dermatitis
Photocontact dermatitis
PHOTOTOXIC


Common
Non immunological

Sunburn

Clinically diagnosed
PHOTOALLERGIC

Less Common

TYPE IV
Hypersensitivity

Eczematous

Photo patch test
Systemic/ topical drugs, chemicals contactants in
combination with UVA spectrum induces
phototoxic and photoallergic reactions.
Phototoxic reactions

Topical:
◦ Perfumes, Dyes, psoralens, tars, plants (lime,
celery)

Systemic:
◦ Psoralen, Tetracycline, Phenothiazine
Photoallergic reactions

Topical:
◦ Perfumes (soaps, aftershave) sunscreens
(PABA)neomycin, halogenated compounds
parthenium (congress grass)

Systemic:
◦ NSAIDS, phenothiazine, thiazides.
Approach to photosensitive disorder

Detailed history :
◦ Age/ Sex
◦ Occupation, Hobbies
◦ Family h/o similar disease
◦ Time interval between exposure & symptoms
◦ Contactant, drug history
◦ Cosmetics, sunscreen usage.
Approach to photosensitive disorder
Clinical diagnosis :

Photoexposed areas:
◦ Face, ‘V’ area& nape of neck, dorsae of hands
& feet, extensors of arms & legs (check
clothing used)

Spared areas:
◦ Under hair fringe, chin, nose, upper eyelids,
behind ears.

Morphological pattern depends on etiology
Investigations

Depending on etiology :
◦ Connective Tissue diseases, Metabolic,
Genetic AnA, dsDNA, porphyrin levels
(blood, urine,stool), Chromosomal
analysis, cell mutation studies, DNA
repair assesment

Biopsy

Photo testing

Photopatch testing
Treatment: Photoprotection

Natural: Ozone, Melanin, Keratin.

Physical: Clothing, broad rimmed hats,
umbrellas.

Topical: Sunscreens, UVA, UVB therapy.

Systemic: Beta carotene, Chloroquin,
Hydroxychloroquin, PUVA
Treatment of causative factor

Removal of offending drug/chemical/contactant

Steroids (topical/systemic)

Immunosuppressives (Azathioprine,
cyclosporin, Thalidomide)
Sunscreens - Topical
Physical

Reflect, scatter light

Zinc oxide

Titanium dioxide

Ferrous oxide
Chemical

Absorbs light &
prevents penetration
through skin

Anthranilates,
benzophenones,
cinnamates, salicylates
Sunscreens - Topical

Broad spectrum - UVA & UVB protective
SPF 15 or higher in Indian skin
Proper application & use in all seasons needed.
Liberal and uniform application to photo exposed
areas, half an hour prior to sun exposure.
1ml – Face
–
Female
1.5ml – Face – Male

Frequent reapplication if involved in vigorous
exercise, swimming.
Sunscreens - Topical

Broad spectrum - UVA & UVB protective
SPF 15 or higher in Indian skin
Proper application & use in all seasons needed.
Liberal and uniform application to photo exposed
areas, half an hour prior to sun exposure.
1ml – Face
–
Female
1.5ml – Face – Male

Frequent reapplication if involved in vigorous
exercise, swimming.
Urticaria

It is a reaction pattern consisting of
erythematous, transient, itchy swellings
(wheals) on the skin

Urticaria is derived from the word “Urtica” (in
Latin = Stinging Nettle)
Pathogenesis
Enhanced vasodilatation + Vaso permeability
Plasma leakage
Wheals
Histamine stimulates nerve endings
Pruritus
Neuro-peptide release
Skin response (flare)


Response to histamine release from cutaneous mast
cells
Often seen with Angioedema
Causes

Exogenous

Endogenous

Physical

Emotional stress

Idiopathic
Contd…
Causes

EXOGENOUS
◦ Inhalants: pollens, house dust, fungi, dander.
◦ Ingestants: Foods: fish, egg, brinjal, food
additives, dyes, preservatives.
◦ Drugs: penicillin, NSAIDs, sulfonamides.
◦ Contactants: beestings, insect bites, plants.
Causes

ENDOGENOUS
◦ Infections:
Gastrointestinal, respiratory, urinary tract
infections
Bacterial, protozoal, helminthic, viral (CMV,
EBV, HSV)
◦ Systemic diseases:
Hashimoto's Thyroiditis
Systemic Lupus Erythematosus
Chronic active hepatitis
Malignancies
Causes
PHYSICAL URTICARIA




Cold Urticaria
◦ Affects hands, ear, nose and lateral thighs
Cholinergic Urticaria
◦ Fever
◦ Hot baths
◦ Exercise-Induced Urticaria
Solar Urticaria (Sun induced)
Pressure
◦ Tight clothing
◦ Soles of foot and other weight bearing points
◦ Dermographism
Types of urticaria by duration:

Acute Urticaria (present hours to weeks)
◦ Idiopathic in 75% of cases

Chronic Urticaria (persistent beyond 6 weeks)
◦ Idiopathic in 95% of cases
◦ May be related to autoantibody to IgE
Clinical features:

Symptoms
◦ Pruritus

Signs
◦ Characteristics
 Hives or wheals
 Spreads with scratching and coalesce to form
large patch

Course of Lesions
◦ Lesions last 90 minutes to 24 hours
Dermographism

Dermographism is a condition where linear
wheals are elicited by stroking or scratching the
skin

These wheals subside within 30 minutes

Some patients have chronic dermographism
which may persist throughout life
Angioedema

Non-pitting subcutaneous swelling
◦ Well demarcated
◦ Distribution

Face
 Hands
 Buttocks
 Genitalia
 Abdomen
 Laryngeal angioedema (Anaphylaxis)

Anaphylaxis is a medical emergency
Workup in a patient of Urticaria
Careful History

Travel and work history

Ingestion of foods, medications, herbals,
vitamins

Recent infection

Negative history makes finding cause more
difficult

Known allergies

Family History of allergy or Thyroid disease
Investigations

Consider brief panel depending on history
i. Hb, CBC
ii. Urine analysis
iii. Stool analysis
iv. ESR
v. Liver Function Tests
vi. TSH
vii. ANA

Skin biopsy if lesion present >24 hrs, consider
urticarial vasculitis

Autologous Serum test
Treatment

Management :
General
◦ Rule out Anaphylaxis
◦ Discontinue offending drugs, food, or behavior
◦ Offer Reassurance
Discuss idiopathic nature of chronic urticaria
Unlikely to identify a specific cause
Contd…
Treatment

Step 1: Non-Sedating Antihistamines (e.g.
Fexofenadine)
◦ Less effective antipruritic as compared to
sedating Antihistamine
◦ Consider for daytime urticaria symptom control

Step 2: Sedating Antihistamines (e.g. Hydroxyzine)
◦
Consider for night time and refractory to step 1
◦ Beware of sedation and risk of fall in older
patients

Step 3: Add H2 Receptor Antagonist (e.g. Ranitidine)
Contd…
Treatment

Step 4: Other anti-histaminics
◦ Doxepin
◦ Cyproheptadine

Step 5: Leukotriene modifier
◦ Montelukast
◦ Zafirlukast

Step 6: Systemic Corticosteroids
◦ Prednisone 20-40 mg PO qd
◦ Caution : Process may flare when steroids are
weaned off
Thank you