TUTORIAL PRESENTATION

NECROBIOTIC DISORDERS

GRANULOMA ANNULARE

Calcott Fox first described ‘ringed eruption of the fingers’ in 1895.

Radcliffe-Crocker called this as granuloma annulare in 1902

It occurs in all age groups but is rare in infancy

Many studies report a female preponderance

ETIOLOGY Etiology is not clearly understood but

triggering factors are identified

INFECTIONS DRUGS Immunization & Other

HPVVARICELLA VIRUS EPSTEIN–BARR VIRUS (EBV) HIVPARVOVIRUS B19 HEPATITIS C VIRUSBORRELIA BURGDORFERISCABIES

Allopurinol, Diclofenac,Quinidine calcitonin,Amlodipine

Insect bite a cat bite waxing-induced pseudofolliculitisTuberculin tests BCG vaccination Hepatitis B vaccination

HLA-Bw35Sun exppsurePUVA Therapy

PATHOGENESIS

The pathogenetic mechanisms that result in foci of altered connective tissue surrounded by a granulomatous inflammatory infiltrate are not understood

Proposed mechanisms include a primary degenerative process of connective

tissue initiating granulomatous inflammation,'s lymphocyte-mediated immune reaction resulting

in macrophage activation and cytokine mediated degradation of connective tissue

a subtle vasculitis or other microangiopathy leading to tissue injury

CLINICAL FEATURES Benign, usually self-limited cutaneous disease that

classically presents as arciform to annular plaques located on the extremities of young people (J Am Acad Dermatol)

The approximate distribution of GA lesions is (Pediatr Dermatol ) 60% isolated to the hands and arms, 20% on the legs and feet, 7% on both upper and lower extremities, 5% on the trunk 5% on the trunk plus other areas.

The plaques may be skin-colored, pink or violaceous in color, and, upon close inspection, are found to be composed of individual small papules measuring a few millimeters in diameter

Stretching the skin enables the papules to be seen more readily.

The surface of the skin over the papules is intact and there is usually no scaling

CLINICAL VARIANTS(FITZPATRICK)

Localized Generalized, Subcutaneous Perforating, and Patch types Linear granuloma annulare Follicular pustular form Papular umbilicated lesions in children

There is overlap between the different variants, and more than one morphologic type may co-exist

LOCALIZED The most common form Usually presents as

annular or arcuate lesion It may be skin colored

erythemarous or violaceous

Usually 1 to 5 cm in diameter

The annular margin is firm to palpation and may be continuous or consist of discrete or coalescent papules in a complete or partial circle

GENERALIZED Can occur upto 15% of

patients characterized by myriad

small skin-colored to pink-violet papules in a symmetric distribution on the trunk and extremities.

Some of these papules may coalesce to form small annular plaques .

Generalized GA later age of onset, poorer response to

therapy an increased prevalence

of the HLA-Bw35 allele In one study of 100

patients with generalized GA, 45% had lipid abnormalities, including hypercholesterolemia, hypertriglyceridemia, or both

PERFORATING

Characterized by trasepidermal elimination of necrobiotic collagen

Superficial papules with central umbilication or crusting with discharge of creamy fluid

Lesion heal with atrophic or hyperpigmented scars.

Can develop over zoster scars and tattos

SUBCUTANEOUS

Large, painless, skin-colored nodules which may be mistaken for rheumatoid nodules, leading to the term pseudorheumatoid nodule.

It has a predilection for children in the first 5 to 6 years of life.

Typical locations include the palms, hands, anterior tibial surfaces and feet, as well as the buttocks, scalp and, rarely, the eyelids.

As many as 50% of patients with deep GA lesions also have associated classic lesions.

DISAESE ASSOCIATION

GA has been described as a paraneoplastic granulomatous reaction to solid organ tumors, Hodgkin disease, non-Hodgkin lymphoma and granulomatous mycosis fungoides In these patients, the clinical pattern is frequently atypical, with painful lesions in unusual locations, including the palms and soles.

Many reports supporting or refuting the association of GA with diabetes mellitus have been published.

In a retrospective study of 84 patients, 12% were found to have diabetes mellitus, and these patients were more likely to suffer from chronic relapsing GA than were non-diabetic patients (Dermatology  1996)

Classic GA and perforating GA may occur in herpes zoster scars

Atypical variants of GA have been associated with HIV infection

HISTOPATHOLOGICALLY

GA is a granulomatous dermatitis characterized by focal degeneration of collagen and elastic fibers, mucin deposition, and a perivascular and interstitial lymphohistiocytic infiltrate in the upper and mid dermis.

The key to the histopathologic diagnosis of GA is the identification of histiocytes in one of three patterns.

Increased mucin is the hallmark of granuloma annulare

The most common is the infiltrative or interstitial pattern(about70%) scattered histiocytes are distributed between collagen fibers.

Degeneration of collagen fibers is minimal, but granular, basophilic mucin deposition between collagen bundles can be highlighted with Alcian blue and colloidal iron stains

The second pattern (25% of cases) is palisading It consists of one to several palisading granulomas with

central connective tissue degeneration surrounded by histiocytes and lymphocytes . Mucin is abundant in the center of the palisaded granuloma, and fibrin, neutrophils and nuclear dust may also be present.

The final pattern is rare, and it consists of epithelioid histiocytic nodules that can resemble cutaneous sarcoidosis

DIFFERENTIAL DIAGNOSIS

TREATMENT

NECROBIOSIS LIPOIDICA

Necrobiosis lipoidica was first described by Oppenheim, in 1930

Named by necrobiosis lipoidica diabeticorum by Urbach, in 1932.

Characterized by sharply demarcated plaques of atrophic yellowish skin, which may ulcerate.

EPIDEMILOGY Female to male ratio is 3:1 Young and early middle age is affected Necrobiosis lipoidica and diabetes mellitus

In a study 11 percent of cases of NL had DM while in similar percentage of patients glucose intolerance is found.

No relation with degree of hyperglycemia and likelihood of NL is found

PATHOGENESIS

The etiology and pathogenesis is not known but some hypothesis are present Immunologically mediated vascular disease has

been suggested as the primary cause of the altered collagen seen in NLD, and this hypothesis is supported by the presence of immunoreactants deposited in vessel walls of lesional as well as uninvolved skin in patients with NLD.(Arch Dermatol )

It is also postulated that the microangiopathic vessel changes seen in diabetic patients could contribute to the development of collagen degeneration and subsequent dermal inflammation

CLINICAL FEATURES

NLD presents clinically with yellow–brown, atrophic, telangiectatic plaques surrounded by raised, violaceous rims, typically in the pretibial region having GLAZED-PORECLAIN appearance.

The lesions start as small, firm, red–brown papules that gradually enlarge and then develop central epidermal atrophy. Lesions are often multiple and occur with bilateral symmetry.

Ulceration occurs in 35% of lesions usually following minor trauma.

Less typical anatomic locations for NLD include the upper extremities, face and scalp, where the lesions may be more annular or serpiginous in configuration and are less atrophic

HISTOAPTHOLOGICALLY The epidermis is normal or atrophic, and absent if

there is ulceration. The dermal changes involve its full thickness, and

often extend into the subcutaneous fat. Early lesions show a perivascular and interstitial mixed inflammatory cell infiltrate.

Areas of necrobiosis are usually more extensive and less well-defined.

There is degeneration of collagen and elastin within lesions .

Histiocytes border the areas of necrobiosis. There are variable numbers of Langhans’ or foreign-body giant cells.

Small, superficial blood vessels are increased in number and telangiectatic

TREATMENT First-line therapy includes potent topical

corticosteroids for early lesions and intralesional corticosteroids injected into the active borders of established lesions.

Other therapeutic modalities include: PUVA therapy Topical tacrolimus Fumaric acid esterst Thalidomide Chloroquine Highdose nicotinamide Clofazimine Pentoxifylline Tretinoin (0.05%) Prostaglandin E1

GRANULOMA MULTIFORME

A chronic granulomatous skin condition, characterized clinically by firm papules aggregated into plaques or forming the edges of annular lesions, and histologically by focal necrobiosis and histiocytic granulomas

The primary event may be sun-induced damage to dermal connective tissue

The upper, uncovered parts of the body are predominantly affected.

The initial lesions are small, flesh-coloured papules which become aggregated into plaques or form the elevated rims of annular lesions.

In larger annular lesions the central area is often hypopigmented.

Pruritus may be prominent The condition lasts for many months or

years, and may persist indefinitely.