Raccoon Eyes in Dermatology Revisited

Introduction Raccoon (syn:Procyon lactor) is a small carnivorous mammal mainly seen in North America. The name raccoon is derived from the native Algonquian word ärähkun, from ärähkuněm (ah-rah-koon-em) meaning “he that scratches with his hands.”[1] Its distinctive facial appearance led to the description of raccoon eyes for periocular ecchymosis or bruising. The spectrum of raccoon eyes has now expanded to a multitude of dermatological conditions as summarized below. Classification The causes for raccoon eyes can be classified as: Traumatic Vascular Metabolic Autoimmune Infectious Neutrophilic Neoplastic Iatrogenic Conditions with Raccoon Eyes Traumatic The raccoon eyes or panda sign is a strong indicator of basilar skull fractures. It presents with bilateral periorbital ecchymosis sparing the tarsal plate due to the orbital septum limiting the spread of hematoma [Figure 1a].[2] Other features include battle sign (mastoid ecchymosis), halo sign (cerebrospinal fluid rhinorrhea), subconjunctival hemorrhage, and hemotympanum. It is an early indicator of subdural or extradural hematoma in the absence of neurological symptoms and requires radiological studies for confirmation [Figure 1b]. Traumatic periorbital ecchymosis in a child should raise suspicion for child abuse and shaken baby syndrome.[3]Figure 1: (a) Raccoon eyes due to bilateral periorbital ecchymosis in basilar skull fracture. (b) Noncontrast computed tomography showing basilar skull fracture in the same patientVascular Vascular causes include thrombosis of major cerebral vessels like cavernous sinus, superior sagittal, and dural sinus. An increase in intravascular pressure can lead to rupture of fragile periorbital vessels in conditions such as pseudotumor cerebri, migraine, and trigeminal autonomic cephalgia.[4] Severe coughing, sneezing, vomiting, and powerlifting by the Valsalva phenomenon cause increased cerebral venous pressures transmitted to the periorbital vessels, causing rupture and ecchymosis.[4] In cases of migraine, there is a release of vasoactive mediators such as serotonin, substance P, endorphins, histamine, and heparin, leading to vasodilation, increased vessel wall fragility, and red blood cell extravasation.[5] Metabolic Raccoon eyes are typical of systemic amyloidosis along with macroglossia, pinch purpura, and waxy translucent papules on the skin [Figure 2]. It is caused by increased vessel wall fragility due to the perivascular amyloid and due to consumption of factor X leading to coagulation defect. It is important to recognize these signs to evaluate for cardiac amyloidosis and the presence of underlying monoclonal gammopathy, especially AL amyloidosis.[6]Figure 2: Raccoon eyes in systemic amyloidosis with periorbital purpura, waxy translucent papules, and macroglossiaAutoimmune Neonatal lupus erythematosus (NLE) presents as a maculopapular rash limited to the periorbital area termed raccoon eyes [Figure 3]. These occur due to the passive transfer of maternal antibodies causing vasculitis limited to the periorbital region and disappear by 6–12 months of age. Complications of NLE include congenital heart block, transaminitis, and thrombocytopenia. Antinuclear antibodies and anti-SSA/SSB antibodies should be screened in both the child and the mother. The mother is asymptomatic in 50% of cases and may develop systemic lupus erythematosus or Sjögren’s syndrome later.[7]Figure 3: Raccoon eyes in neonatal lupus erythematosusThe heliotrope rash of dermatomyositis refers to dusky violaceous erythema, with or without edema, involving the periorbital regions.[8] Heliotrope-like eruptions can be due to drugs like imatinib, or due to adult-onset Still’s disease.[9,10] The presence of Gottron’s papules, V sign, Shawl sign, and Holster sign can differentiate these conditions. Investigations such as muscle enzymes, skin biopsy, electromyography, and myositis-specific antibodies can confirm the diagnosis. Infectious Infectious mononucleosis can cause raccoon eyes along with fever, maculopapular rash, pharyngitis, lymphadenopathy, and hepatosplenomegaly. Hoagland sign refers to bilateral transient upper eyelid edema seen in approximately 15% of the cases. Dengue fever presents with petechial and purpuric lesions due to thrombocytopenia. This can lead to periorbital ecchymosis along with other ocular findings such as conjunctival hemorrhage, vitreal and retinal hemorrhage, choroidal effusions, scotoma, and maculopathy. Kawasaki disease presents with fever, maculopapular rash, strawberry tongue, cheilitis, palmoplantar erythema, cervical lymphadenopathy, nonexudative conjunctivitis, and occasionally, raccoon eyes. Complications include coronary artery aneurysms and sudden cardiac death. Treatment includes intravenous immunoglobulin for cardiac involvement.[11] A Kawasaki disease-like phenotype with raccoon eyes can also occur in multisystem inflammatory syndrome.[12] Neutrophilic Sweet’s syndrome is characterized by an abrupt onset of tender nodules with fever and systemic symptoms. Periorbital erythematous, edematous plaques present as raccoon eyes in Sweet’s syndrome. This is due to the release of neutrophilic mediators such as matrix metalloproteinases (MMP-2, MMP-9) and vasculitis causing vessel wall damage.[13] A similar presentation is also seen in chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperature syndrome, an inherited autoinflammatory syndrome with prominent neutrophilia due to a mutation involving proteasome B8 (PSMB8).[14] Neoplastic Raccoon eyes with periorbital involvement are a common presentation of childhood neuroblastoma in 15–20% of children. The periorbital metastases cause occlusion of the palpebral vessels leading to ecchymosis, edema, proptosis, defective ocular motility, opsoclonus, and finally blindness.[15] These are also seen in the bone scan due to orbital metastasis. Other conditions include lymphoblastic leukemia, Kaposi sarcoma, and chloroma.[15] Periorbital involvement with prominent edema and scaling can occur in cutaneous T-cell lymphoma and can be an early marker of disease.[16] Iatrogenic Raccoon eyes can occur as a part of procedural complications such as post-rhinoplasty, stent placement, kidney biopsy, or endoscopic retrograde cholangiopancreatography.[17] Post-proctoscopic periorbital purpura is a complication of AL amyloidosis. Dermatological procedures resulting in raccoon eyes include ablative laser resurfacing, electrolysis, and hyaluronidase injections for fillers.[18] Conditions That Can Mimic Raccoon Eyes Pemphigus foliaceus Periorbital erosive erythema mimicking raccoon eyes is seen in pemphigus foliaceus, which usually involves the seborrheic regions [Figure 4]. Periorbital involvement occurs due to Koebner’s phenomenon, often with overlying herpes and cytomegalovirus infection. A Tzanck smear, skin biopsy with immunofluorescence, and desmoglein titers can confirm diagnosis.[19]Figure 4: Raccoon eyes in pemphigus foliaceusLichen planus pigmentosus Acquired dermal macular hyperpigmentation (ADMH) encompasses conditions such as lichen planus pigmentosus, ashy dermatoses/ erythema dyschromicum perstans, and pigmented contact dermatitis. They present as slate gray macules which can localize around the eyes, mimicking raccoon eyes [Figure 5a]. Dermoscopy and histology can differentiate them from other mimics.[20] A similar presentation can be also seen in Nevus of Ota [Figure 5b] when present bilaterally and acquired bilateral nevus of Ota-like macules.Figure 5: (a) Periorbital lichen planus pigmentosus as raccoon eyes. (b) Nevus of Ota in the periocular regionApproach The approach to evaluation of a child or adult with raccoon eyes is summarized in Figures 6 and 7.Figure 6: Algorithm for an approach to raccoon eyes in a child. ANA – Antinuclear antibody, CECT – Contrast-enhanced computed tomography, CT – Computed tomography, EBNA – Epstein–Barr nuclear antigen, EBV – Epstein–Barr virus, ECG – Electrocardiogram, ECHO – Echocardiography, ENA – Extractable nuclear antigen, ESR – Erythrocyte sedimentation rate, MIBG – Metaiodobenzylguanidine, NSE – Neuron-specific enolase, PCR – Polymerase chain reaction, VCA – Viral capsid antigenFigure 7: Algorithm for an approach to raccoon eyes in an adult. CRP – C-reactive protein, CT – Computed tomography, DIF – Direct immunofluorescence, ELISA – Enzyme-linked immunosorbent assay, ESR – Erythrocyte sedimentation rate, IgM – Immunoglobulin M, MRI – Magnetic resonance imaging, NS1 – Nonstructural protein 1Conclusion To conclude, raccoon eyes may be a marker of various underlying dermatological conditions. A comprehensive understanding of these diverse presentations of raccoon eyes is essential for accurate diagnosis and appropriate management. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patients have given their consent for their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest. Use of artificial intelligence (AI) The authors confirm that no AI was used for drafting this manuscript.