ALLERGIC DERMATOSIS 

Allergic diseases result from the interaction of antigen & antibodies & subsequent release of mediators that affect various target organs.

Classification of hypersensitivity reactions (by Gell & Coombs)

a)    Type 1 or anaphylactic reaction, which is mediated by Ig E, this mechanism is involved in certain urticarias & reactions to stings.

b)   Type 2 or cytotoxic reaction: This reaction occurs in cases of some drug allergies.

c)    Type 3 or complex reaction is due to in situ complement fixation deposit caused by soluble antigen- antibody complexes. This is the Arthus type reaction that occurs in serum sickness & some drug allergies.

d)   Type 4 delayed (cellular) reaction: This occurs in allergic contact dermatitis.

ALLERGIC CONTACT DERMATITIS

Contact dermatitis is an acute, subacute, or chronic inflammation of the skin caused by an external agent which comes in direct contact with the skin. Environmental & seasonal factors play a role in the incidence of allergic contact dermatitis. Racial factors also play a role, as Caucasians appear to be more susceptible than blacks to sensitization.

Approximately two-thirds of cases of contact dermatitis occur on the hands, are often of an occupational nature, & are of the irritant type.

Contact dermatitis affecting other sites is most the allergic type. Allergic contact dermatitis is due to a Type 4 cell- mediated immune response to an allergen. It is a typical example of the delayed type sensitivity of T cell mediated reaction. It occurs only in individuals who have become sensitized to substance during a previous exposure.

KEY DIAGNOSTIC FEATURES

v  Sudden onset of erythema, oedema, vesicle, bullae, & oozing accompanied by pruritus & burning.

v  Eruption at a localized site.

v  History of exposure to a potential allergen.

v  Positive patch test to suspected sensitizer.

The morphology of eruption may also be helpful. Linear lesions for example are suggestive of plant dermatitis. Allergic contact dermatitis is usually severely pruritic. 

   Allergy to hair dye                      Contact dermatitis caused by Nickel        Severe dermatitis due to elasticized undergarment

Common sensitizers that cause allergic contact dermatitis

Regional clues to sensitizing items

TREATMENT (homoeopathic management)

a)   HOMOEOPATHIC MEDICAL REPERTORY BY ROBIN MURPHY

v  Skin, DERMATITIS: CHAM, HEP, MERC, PULS, RHUST, SIL

        tendency to: CHAM

v  Diseases, DERMATITIS: CHAM, HEP, MERC, PULS, RHUST, SIL

v  Skin, ERUPTIONS itching: ARS, CAUST, CLEM, GRAPH, MEZ, NAT-M, NIT-AC, NUX-V, RHUST, SEP, STAPH, SULPH

v  Skin, ITCHING contact from, agg:ran-b

v  Skin, POISON, oak or ivy: ANAC, CLEM, CROT-T, RHUS-T

b)   SYNTHESIS REPERTORY

v  Skin, ERUPTIONS erythema: Bell, Mez

v  Skin, ERUPTIONS itching: Ars, Caust, Clem, Graph, Mez, Nat-m, Nit-ac, Nux-v, Rhust, Sep, Staph, Sulph

v  Skin, ITCHING contact from, agg:ran-b

c)    KENT’S  REPERORY

v  SKIN, ERUPTIONS itching: Ars, Caust, Clem, Graph, Mez, Nat-m, Nit-ac, Nux-v, Rhust, Sep, Staph, Sulph

URTICARIA

Urticaria (hives) is an acute or chronic allergic dermatosis. It is usually a transient, mild vascular reaction of the dermis characterized by pruritic wheals.

The common mechanism of urticaria is considered to be the release of histamine from mast cells, which causes an increased capillary permeability & vasodilatation leading to the formation of dermal swellings. Most urticarias represent a Type 1 (Ig E) mediated reaction. Acute urticaria is often caused by insect bites or stings, medications, foods like shellfish, pork etc.

CLINICAL FEATURES

The onset is usually sudden with development of blotchy spots which rapidly become white or pinkish wheal or plaques, often surrounded by an erythematous halo. The eruption tends to appear on covered areas, mostly the trunk & buttocks. Acute urticaria is often self limited. Chronic urticaria lasts several weeks to many months.

Clinical varieties:

·         Angioedema

This affects the subcutaneous tissues rather than the dermis & mostly involves the lips, eyelids & genitals.

·         Cholinergic urticria (heat or stress induced)

The lesions are associated with perspiration.

·         Cold urticaria

It is due to cold exposure. Symptoms subside quickly when the affected areas are rewarmed.

·         Contact uticaria

It is due to contact with an external substance.

·         Dermographism

It is a physically induced variety which results from firm stroking of the skin.

TREATMENT (homoeopathic management)

a)   SYNTHESIS REPERTORY

v  Skin, ERUPTIONS urticaria: (→angioedema): Apis, Ars, Astac, Calc, Calc-s, Carbn-s, Caust, Chlol, Cop, Dulc, Hep, Nat-m, Rhust, Sulph, Urt-u

d)   KENT’S REPERTORY

v   SKIN, ERUPTIONS urticaria.

e)    MURPHY’S REPERTORY

v  Skin, URTICARIA, hives: APIS, ARS, ASTAC, CALC, CALC-S, CARBN-S, CAUST, CHLOL, COP, DULC, HEP, NAT-M, RHUST, SULPH, URT-U

v  Diseases, HIVES, urticaria

f)    BOENNINGHAUSEN’S THERAPEUTIC POCKET BOOK

v  SKIN Eruptions Nettle-rash: APIS, CALC-C, CAUST, DULC, HEP, RHUS.

v  SKIN Eruptions, Nodular (Wheals and Hives): APIS, CALC-C, CAUST, DULC, LACH, MEZ, RHUS.

g)   BOGER BOENNINGHAUSEN’S REPERTORY

v  SKIN & EXTERIOR BODY Eruptions urticarious (nettle-rash): APIS, CALC-C, CAUST, DULC, HEP, RHUS

ATOPIC DERMATITIS 

Atopic dermatitis (atopic eczema) is a genetically determined disease in which there is a high personal or familial incidence of allergic conditions. Clinically the disease is characterized by an acute eczematous dermatitis in early life & a chronic lichenified eruption in adolescence.

Various factors such as altered immune defenses, abnormal beta adrenergic receptors & food allergies are the possible causes. Atopic individuals tend to produce high levels of circulating Ig E.

CLINICAL FEATURES

Atopic dermatitis s divided into 3 stages:

·         Infantile

·         Childhood

·         Adolescent/ adult

The infantile stage affect infants aged 2 months to 2 years. It involves mainly the scalp & face sparing the perioral region. The childhood forms are usually less vesicular, drier& more popular. The flexural aspects of elbows & knees are frequently involved. Pruritus is always present & scratching cause lichenification. In the adult form, the eruption is frequently dry & often lichenified. The antecubital & popliteal spaces are usually involved. The cardinal symptom is pruritus.

ALLERGIC DRUG ERUPTIONS 

These are hypersensitivity reactions that result from allergic sensitization to systematically administered drug. Children & the aged appear to be less prone to drug sensitization than adults.

CLINICAL FEATURES 

A drug may be tolerated for weeks or even years without ill effects. But once an individual become sensitized, the reaction usually occurs within minutes to 24 hours. In Steven- Johnson’s syndrome, a severe form of erythema multiforme, there are also mucoal lesions & involvement of internal organs with significant constitutional symptoms.

Some drug eruptions have the appearance of various dermatoses, but with atypical presentation:

• Pityriasis rosea- like eruption

            Frequently due to arenicals & barbiturates.

• Lupus erythematous- like eruption

            May be caused by hydralzine & isoniazid.

• Lichenoid eruption

                  Often due to beta blockers & gold.

• Pemphigus like eruption

           Commonly due to rifampicin.

Course is usually brief if the drug is identified & discontinued.

HOMOEOPATHIC MANAGEMENT

a)   SYNTHESIS REPERTORY