Eczema | EVA Homoeopathy

Dr.APARNA.S. BHMS, Thiruvananthapuram

INTRODUCTION

Dermatology is one of the most important disciplines of medicine, where a disease apprises itself over the skin .The diseases affecting the skin always create mental stress to the patients because of external appearance. So its study, have an important place in the practice of medicine.

Eczema is one of the most common skin diseases affecting humanity from time immemorial. Eczema can very well be called the first illness man could have suffered. We find its descriptions even in the most ancient writings. Perhaps the primitive men feared skin diseases more or less the way we do nowadays with regards to Cancer or AIDS.

Eczema or dermatitis is a reaction pattern that presents with variable clinical and histological findings and is the final common expression for a number of disorders including atopic dermatitis, allergic and irritant contact dermatitis, dyshydrotic eczema, nummular eczema etc. Primary lesions may include papules, erythematous macules and vesicles which can coalesce to form patches and plaques. In severe eczema, secondary lesions from infection or excoriation, marked by weeping and crusting may predominate. Long standing dermatitis is often dry and is characterized by thickened, scaling skin (lichenification).

According to Homoeopathy, it is the outward reflection of a deranged internal economy. The most significant aspect of eczema or rather itch, is its link with the Theory of Chronic Diseases and miasms especially Psora. Dr.Samuel Hahnemann, the Father of Homoeopathy believes that 7/8ths of all the chronic maladies spring from Psora, a constitutional predisposition to a multitude of illnesses , the origin of which can be traced back to a suppressed itch, perhaps , in the preceding generations.

According to Dr.Hahnemann, The oldest monuments of history which we possess show the Psora even then in great development. Moses, 3400 years ago pointed out several varieties. In Leviticus, (chap 13&21, verse 20) he speaks of bodily defects, which must not be found in a priest, who is to offer sacrifice, malignant itch is designated by the word Garab, which the Alexandrian translators(in the Septuagint) translated with Psora agria, but the Vulgate with scabies jugis. The Talmudic interpreter, Jonathan, explained it as dry itch spread over the body; while the expression Yalephed, is used by Moses for lichen, tetters, herpes. The commentators in the so-called English Bible-work also agree with this definition, Calmet among others, saying:

Leprosy is similar to an inveterate itch with violent itching. The ancients also mention the peculiar, characteristic, voluptuous itching, which attended itch then as now, while after the scratching, a painful burning follows; among others Plato, who calls glykypikron, while Cicero remarks the dulcedo of scabies. At that time and later on among the Israelites, the disease seems to have mostly kept the external parts of the body for its chief seat. This was also true of the malady as it prevailed in uncultivated Greece, later in Arabia, and lastly, in Europe during the Middle Ages.

The nature of this miasmatic itching eruption always explained essentially the same. It is identical, therefore, with the ancient form of leprosy; with the St. Antonys Fire or malignant erysipelas, which prevailed in Europe for several countries and then reassumed the form of leprosy, which was brought back by returning crusaders in the thirteenth century. After that it spread more than ever. It was gradually modified by greater personal cleanliness, more suitable clothing and general improvement in hygienic conditions, until it was reduced to a common itch, which could be and more easily removed from the skin by external treatment. But as Hahnemann points out the state of mankind, was not improved thereby; in many respects it grew far worse.

SKIN: EMBRYOLOGY

The skin is derived from three diverse components:

a) The epidermis is derived from the surface ectoderm. At first, it is single layered. By proliferation, it gives rise to typical stratified squamous epithelium. Many of the superficial layers are shed off. These get mixed with sebaceous glands secretions to form a whitish sticky substance (vernix caseosa) which covers the skin of the newborn infant. It has a protective function.

b) The melanoblasts or dendritic cells of the epidermis are derived from the neural crest.

c) The dermis is formed by the condensation & differentiation of mesenchyme underlying the surface ectoderm. This mesenchyme is believed to be derived from the dermatome of the somites.

The line of junction between dermis and epidermis is at first straight. Subsequently, the epidermis shows regularly spaced thickenings that project into the dermis. The portions of the dermis intervening between these projections form the dermal papillae. Later, surface elevations (epidermal ridges) are formed by further thickening of the epidermis in the same situation.

NAIL

They develop from the surface ectoderm, the tip of which thickens to form a primary nail field. Subsequently, this thickening migrates from the tip of the digit onto its dorsal aspect. The cells in the most proximal part of the nail field proliferate to form the root of the nail. Here the cells of the germinal layer multiply to form a thick layer of cells called the germinal matrix. As the cells in this matrix multiply, they are transformed into the nail substance.

HAIR

It is derived from the surface ectoderm. At the site, where a hair follicle is to form, the germinal layer of the epidermis proliferates to form a cylindrical mass that grows down into dermis. The lower end of this down growth becomes expanded and is invaginated by a condensation of mesoderm, which forms the papilla. The hair itself is formed by a proliferation of germinal cells overlying the papilla. As the hair grows to the surface, the cells forming the wall of the down growth surround it and form the epithelial root sheath. An additional sheath is formed by surrounding mesenchymal cells. A typical hair follicle is thus formed.

SEBACEOUS GLANDS

It is formed as a bud arising from the ectodermal cells forming the wall of a hair follicle.

SWEAT GLANDS

It develops as a down growth from the epidermis. The down growth is at first solid, but later canalized. The lower end is coiled and forms the secretory part of the gland.

MAMMARY GLANDS

Developmentally, they are derived from sweat glands and therefore, it lies in the superficial fascia. The epithelial mammary bud appears at the 35th day of the intrauterine life. By the 37th day, a series of mammary bud extending on either side of the midline on the ventral surface of the trunk, extending from axilla to the inguinal region develops. These are called mammary ridges or milk line. Most of the line soon disappears. Each mammary gland develops from a part of the line that overlies the pectoral region. From each mammary bud, 16-20 solid outgrowths arise and grow into the surrounding dermis. Then the mammary bud as well as the outgrowth becomes canalized. Terminal parts of the outgrowths proliferate to form the secretory elements of the gland.

The proximal elements of each outgrowth, forms one lactiferous duct. The ducts at first open into a pit, formed by the cavitations of the original epithelial thickening. This pit is called the mammary pit. The growth of the underlying mesoderm progressively pushes the wall of the pit outwards, until it becomes elevated above the surface and forms the nipple.

SKIN: ANATOMY

The skin is the protective covering of the body. With all its specialized derivatives, it makes up the integument, which covers the entire surface of the human body.

The skin is composed of a superficial epithelial layer- the EPIDERMIS and an underlying connective tissue layer, the DERMIS/CORIUM. Beneath the corium, is another connective tissue layer, the HYPODERMIS or subcutaneous layer. The free surface of the epidermis is marked, by a network of linear furrows and ridges.

Structure of epidermis

The epidermis is composed of non vascular stratified epithelium. Its usual thickness is between 0.07 mm&0.12mm.In soles and palms; it may range from 0.8-1.4mm. The epidermis is mainly divided into:

a) Keratinizing /Malphigian system(keratinocytes) which forms the bulk

b) Pigmentary system(melanocytes) which produce the pigment

In addition to keratinocytes, melanocytes, Langerhan cell& indeterminate cell in the epidermis, Merkel cell/Haascheiben/touch cells are found at the base of the epidermal rete ridges and they are in contact with nerve fibrils. They are mostly present in palms, soles, nail beds, oral & genital epithelium and act as slow touch receptors.

The main layers of epidermis, seen in microscopically in a section perpendicular to the skin surface are:

Basement membrane

It forms the junction between epidermis and dermis. Electron microscopic studies show half desmosomes which anchor basal cells to basal lamina. Extending from the basal cell membrane is anchoring dermal filaments. Pemphigoid antigen and laminin are located between the basal cell and basal lamina. This area is 35-45mm thick called lamina lucida. The basement membrane is considered as a porous, semi permeable filter which permits exchange of fluid and cells between the epidermis and dermis. It is made up by Type IV collagen. It is a PAS-positive membrane.

Structure of the dermis(cutis vera or corium)

Dermis is profusely supplied with blood vessels. It is divided into papillary and reticular dermis. It contains connective tissue fibres, cells and all dermal appendages. Connective tissue is mainly formed by 3 components collagen fibres, elastic fibres, and ground substance. The most abundant constituent is collagen. All these are produced by fibroblast. Beneath the basement membrane are distributed many blood vessels forming a capillary network which ends up as a loop into the dermal papillae. These papillae are microscopic finger-like processes projecting into the epidermis which is moulded over and attached to them. These projections are called rete ridges. The connective tissue cells in the dermis are spindle shaped. Thickness of the dermis is 1-3mm.

On microscopic section, in addition to the above structures, hair follicles, sweat & sebaceous glands, plain muscle fibres, Pacinian and Meissners corpuscles are seen. Adipose tissues are present mostly in deeper parts. There are a few round cells, an occasional fibrocyte and few pigment-carrying histiocytes called melanophores. There are rich capillary beds in the papillae and around the appendages and in sub-papillary plexus. Deep reticular plexus is less rich. In the deeper layer of dermis, there is arterio-venous anastomosis (Suquet-Hoyer canal) surrounded by sphincter-like group of smooth muscles under autonomic control and ovoid smooth cells known as glomus cells. Glomus cells are under the control of sympathetic nervous system. A small nerve is associated with every glomus and they respond to various pharmacologic agents and cause vasoconstriction.

Skin is richly innervated by myelinated and non-myelinated sensory fibres and via non-myelinated autonomic fibres supplying blood vessels and appendages. Conspicuous nerve supply consists of plexus in the papillae, Meissners corpuscle, Pacinian corpuscles, and Merkels disc and nerve endings in basal layer of the epidermis.

SEBACEOUS GLANDS

They are scattered all over the integument except palms of the hand, soles and sides of the feet. They occur in association with hair follicles except in eyelids, lip margins, external auditory meatus, nipples, and anus and around external genitalia, as at these sites, they are more superficial. They are numerous and large on scalp, forehead, ears, face, sterna and interscapular regions. In hairy portions, the ducts open into hair follicles otherwise directly on the skin surface. One or more glands maybe attached to one hair follicle. Meibomian glands, mammary glands and smegma glands of penis are modified sebaceous glands. Perspiration and hot climate stimulates sebum production. They are more active at and after puberty, during menstruation and pregnancy.

SWEAT GLANDS

They are of two types:

HAIR

It is found in every body part except palms, soles, dorsal surface of terminal phalanges, inner surface of labia, prepuce and glans penis. There are 3 types of hair:

a) Long, medullated, pigmented hair seen on scalp

b) Short ,fine, non medullated and non pigmented lanugo hair seen in women, children, face and trunk of adults(vellus hair)

c) Thick bristles seen in the nose and ear.

Hair grows about 1-2 cm per month. Hair follicle and its hair can be anatomically, divided into 3 segments: infundibulum, isthmus and inferior. The lower part of the hair is the site of growth. Hair growth is cyclical consisting of 3 phases- growing (anagen), involutionary (catagen) and resting (telogen).

NAILS

These are semi-transparent, plate-like horny structures, covering the dorsal surfaces of the distal phalanges of the fingers and toes. The proximal edge of the nail is known as the root nail. The visible portion of the nail is the nail plate. It is semi-transparent and looks red due to abundant vascular supply in the nail bed. The more opaque and whitish lunar portion of the nail plate near its root is known as the lunula. The surface of the sin on which the nail rests is known as the nail bed. The fold of the skin, surrounding the lateral and proximal borders of the nail is known as the lateral and posterior nail folds.

SKIN : PHYSIOLOGY

The following are, the functions of the skin:-

ECZEMA

Dermatitis and eczema are among the most common dermatological problems accounting for 25-30% of all dermatoses. The terms dermatitis and eczema are synonyms and the two are interchangeable. In the developed world, eczema accounts for a large proportion of skin disease, in both developed and community based populations. It is estimated that 10% of people have some form of eczema at any time, and up to 40% population, will have an episode of eczema during their lifetime.

DEFINITION

The term eczema is derived from the Greek word, Ekzein, (Ec means out, and Zeo means boil). It looks as if skin is boiling out. Eczema is defined as an inflammatory disorder or reaction pattern of skin, to external or internal stimuli, characterized by erythema, oedema, vesiculation, oozing, crusting, papules, scaling and lichenification. It is a catarrhal inflammation of a sensitive skin. The Hindustani name is Chambal.

Although eczema and dermatitis are synonymous, Hebra says Eczema is what looks like eczema. Dermatitis literally inflammation of skin and denotes all types of cutaneous infections while eczema is a specific type of allergic cutaneous manifestation of antigen-antibody reaction. It is characterized by superficial inflammatory oedema of the epidermis associated with vesicle formation. Hence all eczema is dermatitis, but not all dermatitis is eczema.

PREVALENCE AND INCIDENCE

Eczema can affect people of any age, although the condition is most common in infants and about 85% of people have an onset prior to 5 years of age. Eczema will permanently resolve by age 3 in about half of affected infants. In others, the condition tends to recur throughout life. People with eczema often have a family history of eczema or other allergic conditions such as asthma or hay fever. Up to 20% children and 1-2% are believed to have eczema. Eczema is slightly more common in girls than boys. It occurs in all races. It is not contagious but since it is believed to be partially inherited; it is common to find members of the same family affected. There are proportionately more cases in the summer months while exogenous forms are more frequent in winter. Exogenous forms are low in 5-14 age groups, increasing thereafter in males. Housewifes dermatitis is common in 20-40 years age group.

STAGES OF ECZEMA

The natural history of eczema is diagrammatically represented as follows:

Erythema

Papules with oedema

Vesicles

Weeping, crusting pustules Lichenification

Scaling

Healthy skin without scars

The morphoclinical classification into acute, sub acute and chronic stages helps us to decide about the prognosis and line of symptomatic treatment.

Clinically, an eczematous disease may start at any stage and evolves into another.

STAGES OF ECZEMA

Acute eczema blisters

3.Chronic eczema

Thick lichenified skin

HISTOPATHOLOGY

The histopathological features of eczema reflect a dynamic sequence of changes resulting from inflammation of the epidermis and the underlying dermal structures. These vary with intensity and stage of eczematous process and are frequently modified by secondary events such as trauma and infection.

Epidermal changes

The essential feature is spongiosis, an intercellular oedema that leads to stretching and eventual rupture of the intercellular attachments with the formation of primordial vesicles. These commonly occur in discrete foci and in the mid-epidermal region. On the palms and soles, the vesicles do not rupture easily and become large by coalescence. There is a variable infiltration of the epidermis by lymphocytes. Accelerated epidermal activity lead to acanthosis but if spongiosis is intense, disintegration of the suprapapillary epidermis may cause clefts to form, to expose the underlying dermis.

In the sub acute stage, spongiosis diminishes and increasing acanthosis is associated with formation of a parakeratosis horny layer. This often contains layers of dried up serum and pyknotic nuclei of inflammatory cells. Later, the rete ridges become elongated and broadened and hyperkeratosis replaces parakeratosis. The changes are then those of lichenification.

Dermal changes

Vascular dilatation may be the earliest stage and is marked in all stages. The papillary vessels are especially involved and in lichenification may become tortuous. The infiltrate is predominantly lymphocytic, though polymorphs and eosinophils may occur in very acute eczema and eosinophils in particular in eczematous drug eruptions. In the presence of infection, polymorphs may invade the epidermis. In grossly lichenified eczema, prurigo and exfoliative dermatitis, the infiltrate is mixed and maybe done as to stimulate a granuloma.

Complications: The trauma of rubbing or scratching may cause superficial erosions, haemorrhage or subepidermal fibrinoid changes. While some degree of lichenification is always present during a prolonged attack of eczema, it is particularly prominent in atopic dermatitis and has been referred to as neurodermatitis reaction. At times, extreme hyperkeratosis and papillomatosis develop. With secondary infection, the formation of follicular or subcorneal pustules stimulates the appearance of impetigo, though typical eczematous changes are visible at the edges of the lesion.

Changes in the various stages of eczema

On the palms and soles, the resistance of the thick stratum corneum delays the rupture of the vesicles, which tend, in consequence to become large and bullous, by coalescence. In the weeping stage, there is thinning or destruction of the suprapapillary epidermis, which may reach the underlying dermis.

Basis of pathological changes

The changes in eczema have been described as a series of chain reactions which take place in the epidermis and proceed from a primordial vesicle to the extrusion, after more or less spongiosis and exocytosis, of a parakeratotic scale. Spongiosis and the presence of primordial vesicle are important in the histological diagnosis of most chronic lesions.

In light and electron microscope studies carried out experimentally, produced allergic contact dermatitis, the earliest changes consist of vasodilatation and extravasations of monocytes from the vessels, followed by spongiosis as they migrate into epidermis. In irritant dermatitis, primary epidermal damage may progress to subepidermal blister formation.

HISTOPATHOLOGY OF ECZEMA

CLASSIFICATION OF ECZEMA

Classification of eczema is not well established owing to a lack of a definitive nomenclature and aetiologies. For practical purposes, eczema has been grossly divided into 2 main groups:exogenous&endogenous. In exogenous eczema, the causative factor is an exogenous one coming from outside the body, whereas in endogenous eczema,the factor is an internal one. The term endogenous eczema, has no distinct scientific boundary at present. Basically,endogenous eczemas are those group of eczematous disorders in which the precipitating factors are acting from within the body, and not from outside.However,many eczemas lie within the twilight zone of exogenous and endogenous eczemas. In these cases, both exogenous and endogenous factors simultaneously act as causative factors. Moreover, the same type of eczema may sometimes be provoked by external factors and sometimes by internal ones. Often, both exogenous and endogenous eczemas may be present at the same time in a patient.

10. Dermatophytide

11. Secondary eczematization

ETIOLOGY

Basically, two factors are involved. Firstly, an allergic or a sensitive skin; and, secondly, exposure to an irritant. Darier has correctly said that, there is no eczema but an eczematous patient. The general predisposing causes are age, familial predisposition, allergy, debility climate and psychological factors. Eczema usually occurs in infancy, at puberty and at time of menopause. Familial sensitiveness is an important factor. There is usually a personal or family history of allergy i.e. asthma, eczema, hay fever etc. Genetic predisposition is responsible for the preponderance of eczemas in certain families and their absence in others, general physical debility predisposes to eczemas by lowering the resistance of the individual. Climate extremes like heat, dampness and severe cold and also psychological stresses promote the development of eczema. Local factors like xeroderma or ichthyosis, a greasy skin, hyperhidrosis, varicose veins causing congestion and focus of lowered resistance, hypostasis or chilblains predispose to eczema development. In the dry winters of northern India, crackling of the integument of exposed parts may result in eczematization-eczema crackle. There is variety of exciting and aggravating factors like chemicals, plants clothes, drugs, diet, trauma etc.

To summarize:

VARIETIES OF ECZEMA

A. Atopic dermatitis

Synonyms: Besniers prurigo, infantile eczema, flexural eczema, Asthma-eczema syndrome

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Eczema | EVA Homoeopathy