11/6/2011

PANNICULITIS: WHAT SHOULD A DISCLOSURES RHEUMATOLOGIST KNOW?

Lela A. Lee, MD There are no commercial Professor of and relationships relevant to this talk. Medicine, University of Colorado Director of Dermatology, Denver Health

WHEN TO CONSIDER THE DIAGNOSTIC REFERENCES / EBM CATEGORY OF 1. Patterson JW: Panniculitis. In Dermatology. JL Bolognia JL Jorizzo, RP Rapini, eds. Elsevier • When palpation of lesions is consistent with a Ltd., London. 2nd ed. 2008. Pp. 1515-1535 depth of involvement that is in the 2. Mert A, Kumbasar H, Ozaras R, Erten S, Tasli L, . Tabak F, Ozturk R: nodosum: an evaluation of 100 cases. Clin Exp Rheumatol • In general, palpation is more important than 2007;25:563-570. visual inspection in suspecting the diagnostic 3. Martens PB, Moder KG, Ahmed I: category of panniculitis. panniculitis: clinical perspectives from a case series. J Rheumatol 1999;26:68-72

WHY IS PANNICULITIS CHALLENGING?

• “Panniculitis is diagnostically challenging for • Insufficiently specific clinical appearance – dermatologists and pathologists.” JW While there are numerous conditions that can Patterson cause panniculitis, most present as deep • “The histologic diagnosis of panniculitis erythematous nodules and plaques. remains one of the most difficult areas in • Limited ways in which the subQ fat can dermatopathology.” JE Fitzpatrick respond to – The fat contains only fat lobules, fibrous septa, nerves, and blood vessels.

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GENERAL ETIOLOGIC CATEGORIES WHY IS PANNICULITIS CHALLENGING? AND EXAMPLES • Panniculitis is relatively uncommon, and many entities that cause panniculitis are rare. With the • (bacteria, mycobacteria, fungi) possible exception of , there are few large studies of specific entities. • Trauma (cold , injections) • Some terminology is confusing and/or outmoded. • Enzymatic destruction (pancreatic panniculitis) In some cases, there has been too much splitting • Malignancy (T cell ) (e.g., different names for stasis panniculitis) and • Deposition (, calciphylaxis) in others, too much lumping (e.g., the term “Weber-Christian disease” for a variety of • Inflammation (erythema nodosum) conditions such as alpha-1-antitrypsin deficiency, factitial panniculitis, lymphoma).

CLUES FROM CLINICAL EXAM: LOCATION • Erythema nodosum – anterior lower legs • – posterior lower legs • Stasis panniculitis – medial lower legs • Alpha-1-antitrypsin deficiency – buttocks, flanks, and thighs • Lupus panniculitis – face, scalp, upper arms, breasts, upper trunk, buttocks, thighs

CLUES FROM CLINICAL CONTEXT: CLUES FROM CLINICAL CONTEXT: EXAMPLES AGE • Subcutaneous fat necrosis of the newborn – • – pancreatic fat necrosis uncommon; occasionally associated with • Alpha-1-antitrypsin deficiency panniculitis hypercalcemia; usually resolves spontaneously • Silicone injection – foreign body panniculitis • – rare; severely ill premature neonates; poor prognosis • Behcet’s – erythema nodosum • Cold panniculitis – “popsicle panniculitis”; • – rheumatoid brown fat more susceptible; expect spontaneous resolution

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DIAGNOSIS HISTOLOGIC EXAM

• Diagnosis in some cases may reasonably be • Is the pathology primarily in the fat? made by clinical evaluation. • Is the panniculitis predominantly septal, • In many cases of acute panniculitis, and in lobular, or mixed? most cases of chronic panniculitis, histology • What is the inflammatory infiltrate (e.g., with clinical correlation is required. neutrophils, lymphocytes, eos)? • If is taken, it should include a generous • Is there ? sample of the subcutaneous tissue. That • Other (necrosis, organisms, crystals, calcium, usually means excisional biopsy. foreign material)

HISTOLOGIC DX’S OF PANNICULITIS IN OVERVIEW OF THIS PRESENTATION A DERMATOPATHOLOGY REFERRAL PRACTICE • Common and less common (but not rare) panniculitides: erythema nodosum, stasis • 40% erythema nodosum panniculitis, factitial panniculitis, erythema • 31% panniculitis not otherwise specified • 11% lupus panniculitis induratum, and lupus panniculitis • 7% stasis panniculitis • Panniculitis related to rheumatic diseases: • 3% factitial lupus, dermatomyositis, PSS / , • 8% miscellaneous dx’s polyarteritis nodosa, • Focus on clinical and histologic findings **courtesy of James E Fitzpatrick, MD

ERYTHEMA NODOSUM

© 2001-2011, DermAtlas • The most common form of panniculitis • More common in women, more common in 2nd through 4th decades • Crops of painful nodules on the shins and sometimes thighs and forearms • Can have arthralgias, , and • Usually lasts a few weeks and resolves spontaneously, but recurs in some cases © DermAtlas; http://www.DermAtlas.org

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ERYTHEMA NODOSUM – CAUSES ERYTHEMA NODOSUM – CAUSES

• Idiopathic – approximately 50% • Sarcoidosis • Streptococcal infection – probably the most • Inflammatory bowel disease, esp. Crohn’s common cause found • Medications, esp. oral contraceptives • Other : coccidiomycosis, bacterial • (less common) gastroenteritis, viral URI, TB – prevalence of a • Behcet’s (common in highly endemic areas – particular infection depends on prevalence in less common in the US) the general population – e.g., TB more ’ common in countries where TB is prevalent • Sweet s syndrome (less common) • Many rare associations reported

ERYTHEMA NODOSUM HISTOLOGY ERYTHEMA NODOSUM WORK-UP • Prototype of • Biopsy not always indicated. E.g., young, • Miescher microgranulomas (small septal healthy person with strep infection and self- granulomas with clear centers) not always resolving EN – Bx leaves significant scar and present but near-pathognomonic of EN may be slow to heal. • When inflammation is severe and extends into • Search for underlying cause should be the lobules, definitive dx can be difficult directed by clinical context. • Caveat: “On more than one occasion, I have • More comprehensive evaluation may be seen an apparent EN with a septal pattern appropriate for more prolonged and turn out to be PAN when the block was symptomatic EN. leveled.” JE Fitzpatrick

ERYTHEMA NODOSUM RX STASIS PANNICULITIS • Synonyms: , sclerosing • Leg elevation, support stockings, NSAIDs for panniculitis, hypodermitis sclerodermiformis, idiopathic cases chronic panniculitis with lipomembranous • Treat underlying cause if one is found. changes • Many other treatments have been used for • Relatively common - likely underappreciated EN, but no clearly superior treatment. • One or both lower legs, often medial • Usually occurs in the setting of venous insufficiency • Can occur in other areas of stasis, e.g., abdominal pannus or breasts

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STASIS PANNICULITIS • Acute phase may be confused with or erythema nodosum • Chronic phase has sclerosis • On the legs, the sclerosis may give the appearance reminiscent of an inverted wine bottle or piano leg • Biopsy not always necessary, but biopsy findings often sufficiently diagnostic when combined with clinical correlation.

FACTITIAL PANNICULITIS FACTITIAL PANNICULITIS

• Induced by deliberate human action – usually • Unless the histologic diagnosis is self-induced straightforward, panniculitis specimens should • Atypical locations, unusual shapes of lesions be polarized to check for foreign material. • Patient typically denies self-injection • In cases where oils have been injected, there • Many substances reported – oils, urine, feces, may be holes where the material washed out drugs, food, etc. during processing. • Lesions may be infected, suppurative, and/or ulcerative

ERYTHEMA INDURATUM ERYTHEMA INDURATUM • Nodules on lower legs • • Typically in young to middle-aged women Mixed lobular and septal panniculitis – sometimes entirely lobular – with vasculitis • Clinically similar to e nodosum, but more • often on posterior lower legs – much clinical E induratum and used overlap synonymously by some. Others reserve the term “nodular vasculitis” for cases • There is a well-established association with unassociated with TB. TB, but EI can be idiopathic or associated with other infections or drugs.

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LUPUS PANNICULITIS

• Distinctive locations on face, scalp, upper trunk, breasts, upper arms, buttocks, thighs • May have concurrent discoid lesions • A small percentage, perhaps 10%, have SLE. • Overlying often feels bound down. • Atrophy is common and often disfiguring. • Treatment is usually with antimalarials.

LUPUS PANNICULITIS • Histologic findings are sometimes diagnostic, particularly if there is an overlying discoid lesion. In the fat, there is a lobular or mixed pattern of inflammation with hyaline necrosis, mucin, lymphocytes, and lymphoid follicles. • Direct IF is often positive, but usually not necessary. The distinct distribution of lesions together with histologic findings consistent with, even if not diagnostic, for LEP usually suffice to make the diagnosis.

LE PANNICULITIS HISTOLOGIC DERMATOMYOSITIS AND DIFFERENTIAL DX PANNICULITIS • Panniculitis rare in DM • Some cases of subcutaneous panniculitis-like • Cases reported have a distribution and T-cell lymphoma show vacuolar interface dermatitis and abundant dermal mucin in histology somewhat similar to lupus panniculitis addition to a lobular lymphocytic infiltrate. • Lipoatrophy without preceding lesions of

panniculitis has been reported, mainly in juvenile DM, in association with hyperlipidemia and insulin resistance.

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MORPHEA / PSS MORPHEA HISTOLOGY • Inflammation in the fat may occur in both morphea and PSS, although it is typically more • Septal panniculitis with lymphocytic infiltrate pronounced in morphea. and dermal and subcutaneous sclerosis • Inflammation in morphea can be in the • Histology often diagnostic, although (typical morphea), fat (subcutaneous morphea distinguishing between different subtypes of / deep morphea), or fat and fascia (deep morphea requires clinical correlation morphea / morphea profunda). • Eosinophilic fasciitis may coexist with morphea.

POLYARTERITIS NODOSA CUTANEOUS PAN

• Classic PAN: medium-sized vessels – ulceration, • Associations reported include hepatitis B, necrosis, livedo reticularis, SC nodules that may , and Crohn’s disease follow the course of arterioles • Not associated with significant internal • Primarily cutaneous PAN: arterioles in SC and disease, but course may be chronic and lower dermis – SC nodules and livedo relapsing reticularis • Treated relatively conservatively • EN in clinical differential of cutaneous PAN, but not expected to have livedo reticularis

SARCOIDOSIS TAKE-HOME POINTS

• Erythema nodosum often occurs as part of • While biopsy is often important for diagnosis, Löfgren’s syndrome, with bilateral hilar the pathology report should rarely be used as lymphadenopathy and acute iridocyclitis – the final or only determinant of diagnosis. identifies a good prognostic subset • Clinical and histologic correlation is often • Subcutaneous nodules may occur in required. sarcoidosis. • In patients who have rheumatic diseases, consider in the differential the more common forms of panniculitis, even if they are not related to the patient’s rheumatic disease.

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