Cat Scratch Disease – The Inconspicuous Cause of Cervical Lymphadenopathy

ABSTRACT

Bacterial cat scratch disease (CSD), also called cat scratch fever or subacute regional lymphadenitis, affects lymph nodes draining from the implantation site. Bartonella henselae causes most CSD and could be regarded as a cause of concern for acute lymphadenopathy in individuals of all ages. CSD frequently resembles cervical lymphadenopathy or submandibular gland disorders, making diagnosis difficult. This study describes a 12-year-old girl who contracted cat scratch disease with swelling of submandibular lymph nodes following intimate contact with a pet cat.

INTRODUCTION

Cat scratch disease (CSD), called cat scratch fever or subacute regional lymphadenitis, is a bacteria related infection of lymph nodes from the implantation region. CSD is caused by Bartonella henselae, a gram negative rod. CSD should be regarded as a cause of concern for acute lymphadenopathy in individuals of all ages. CSD could resemble cervical lymphadenopathy or submandibular gland disease, making diagnosis challenging.[1,2] This case has an instance of a pet cat exposure, clinically manifesting as submandibular lymphadenitis.

CASE REPORT

After two months of right lower jaw pain and edema, a 12-year-old girl visited our medical facility. The swelling started tiny and caused a dull ache that worsened with touch and alleviated itself. The patient felt pain and intraoral sinus opening associated with the right lower first molar, which was removed in light of a poor prognosis. No major medical history was disclosed. Extra oral examination revealed a right lower jaw facial asymmetry without a mouth opening constraint. Figure 1 reveals a diffuse swelling of 5 × 3 cm was found over the lower right submandibular area, reaching superiorly to the lower border of the mandible, anteriorly 5 cm to the mandibular angle, and posteriorly to the sternocleidomastoid mastoid boundary. It was oval with a smooth surface, undefined edges, and without skin color changes. The swelling was firm in consistency, movable, tender, and not affixed to the connective tissue underneath. On palpation, there was no localized increase in temperature. On intraoral inspection, the removed socket healed well. The prior experience of tooth extraction, which may have caused the infection, led to a tentative diagnosis of right submandibular lymphadenitis. Intra-oral periapical, panoramic, and CBCT showed minor osteomyelitis alterations in the removed socket, suggesting chronic suppurative localized osteomyelitis [Figure 2].

Figure 1.

Preoperative clinical manifestation of submandibular swelling

Figure 2.

CBCT showing bony changes in the mandible

After sequestration, antibiotics were given. After one week, the patient was reviewed, but edema and symptoms did not decrease. Ultrasonography of the neck showed several enlarged cervical lymph nodes in levels IB, II, and III, with some losing fatty hila and cortical thickening. MRI showed hypointense right submandibular lesions with minimal cystic/necrotic regions. For further inquiry, FNAC of the right submandibular lymph node showed dispersed epithelioid granulomas, lymphoid cells with bare nuclei, and caseous necrotic components, suggesting Koch’s lymphadenitis. Inflammatory lymphadenitis due to persistent osteomyelitis, tuberculous, and idiopathic lymphadenitis were differentiated. Two weeks of empirical antibacterial treatment (Inj. Ceftriaxone, sulbactam, Inj. amikacin) did not relieve symptoms. A short course of anti-tubercular medication was administered with antibiotics. However, Mantoux, AFB, chest X-ray, and Real-time polymerase chain reaction for mycobacterium tuberculosis were negative and tuberculosis was ruled out.

Histopathological examination of the excised right submandibular lymph node showed numerous epithelioid granulomas with core suppuration containing neutrophils and rare Langerhans cells, Warthin starry stain positive [Figure 3]. These data suggested CSD. During further history taking, the patient mentioned having been exposed to a pet cat, which could be the cause of CSD. The diagnosis was established by IgG and IgM immunoassay.

Figure 3.

Shows histopathological examination - Warthin starry stain positive

DISCUSSION

Limited diagnostic procedures and documentation make it difficult to determine the prevalence of the illness. Since 1992, Bartonella henselae has been identified as the main cause of CSD. Cat saliva and contamination from erythrocytes can spread to humans through bites and scratches. Patient immunological state strongly impacts the clinical appearance of B. henselae infestations. Immunocompetent individuals usually have classic CSD, characterized by a granulomatous skin lesion that appears 3-10 days after exposure to an infested feline. The evolution of CSD involves swelling of regional lymph nodes. The classic CSD often involves localized lymphadenopathy and a rash, and is typically self-limiting. CSD can be prevalent, especially among immunocompromised children. This case involved a domestic cat as the vector, resulting in self-limiting localized lymphadenitis in the submandibular area.Osteomyelitis changes in the jaw were seen.[2] No systemic changes were seen.

Lymphadenopathy is the primary clinical sign of CSD, occurring in 80% of cases. Atypical CSD symptoms, including lymphadenopathy, impact organs such the eyes, liver, central nervous system, skin, and skeleton in 5% to 25% of cases. The location of lymphadenopathy in CSD depends on the inoculation spot. A study of 1200 persons with CSD found that 48.8% of those affected had involvement in their axillary lymph nodes.[1] Cervical or submandibular involvement was observed in 28.3% of the population. In their study of 246 CSD patients, Hamilton et al.[2] found that 43% of patients had neck infestation, followed by 38% and 20% of individuals with axilla and groin involvement. Additionally, 37% of patients reported lymph node enlargement in 11 locations. Classical CSD is uncommon in individuals with weak immunity. Individuals with Bartonella infections may experience bacillary angiomatosis, peliosis hepatis, and bacteremia.

Diagnosing CSD might be problematic due to its similarity to other cervical lymphadenopathy or submandibular gland illnesses. Early diagnosis of inflammatory chronic lymphadenitis was based on oral foci. The FNAC results for Koch’s lymphadenitis initially suggested tuberculosis, but were later ruled out. CSD should be investigated for individuals with previous cat exposure and lymphadenopathy or cutaneous lesions. While cat scratches, bites, or licking are relevant, they are not necessary for diagnosis. A thorough medical history, full blood count, sedimentation rate, tuberculin test, and some serological testing can expand diagnostic options.[3]

A considerable number of instances remain undiagnosed. Serology is the most accessible method in diverse circumstances. Although positive serology has great specificity, the negative predictive value ranges from 54% to 74%, depending on the IgM or IgG subclass and assay used.[4] B. henselae was identified as the likely cause owing to clinical presentation, but Bartonella quintana can also cause lymphadenitis and infest cats and feline fleas. A titer of ≥1:256, IgM ≥1/80, or IgG ≥1/512 indicates IgM and/or IgG-positive antibodies.[5] PCR and Warthin-Starry silver stain procedures provide as definitive CSD tests.[6]

The case involves a cat scratch, lymphadenitis, Warthin-Starry silver stain histology, and IgG and IgM serological tests that confirm the diagnosis. Consider cautious CSD management as it can be harmful in immunocompetent persons. However, antibiotic treatment is necessary for lymph nodes and systemic issues. Antimicrobial chemotherapy for CSD may shorten illness duration and prevent organ issues with antibiotic treatment.[7] Additionally, corticosteroids can reduce the need for surgery in severe or antibiotic-resistant CSD by alleviating widespread symptoms and lymph node involvement. Refractory patients may undergo surgical therapy, including lymph node excision and biopsy. [8,9] Antibiotic treatment and surgical removal of the submandibular lymph node were administered in this case.

CONCLUSION

CSD is rare and commonly misdiagnosed because it resembles other cervical lymphadenopathy conditions, notably dental foci-associated inflammatory lymphadenitis, and tuberculous lymphadenitis. Due to their self-limiting nature, most of the cases are not detected or reported. Cat scratch or bite, localized lymphadenitis, Warthin starry silver stain, IgG and IgM titers, and PCR aid in confirming the condition.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.