Discussion
According to the World Health Organization (WHO), one of the following
three features are essential for the diagnosis of leprosy:
- Definite loss of sensation in a pale (hypopigmented) or reddish skin
patch
- A thickened or enlarged peripheral nerve with loss of sensation
- The presence of acid-fast bacilli in a slit-skin
smear.5,11
Musculoskeletal symptoms such as arthritis are the third most common
presenting manifestation of leprosy, after neurological and cutaneous
features, and can mimic more common disorders such as rheumatoid
arthritis (RA).12 Clinicians should be aware of this
disease since some form of joint involvement is reported to occur in 75
% of cases of leprosy and at times may be the only obvious
manifestation.9,13 Sometimes, patients with leprosy
were treated for SLE, RA, dermatopolymyositis, and systemic
vasculitis.14 Leonine facies and madarosis are one of
the hallmarks of lepromatous leprosy.2 Radiographic
changes in RA are usually more pronounced than those in leprosy
arthritis.15 Early diagnosis and a full course of
treatment are critical for preventing lifelong neuropathy and
disability. Treatment consists of combination of three drugs: Dapsone,
Rifampicin, and Clofazimine six months for paucibacillary and 12 months
for multibacillary leprosy.5In patient with inflammatory rheumatic disorder prolonged use of
steroid, immunosuppressive therapy, and biological agents might flare up
the latent form of tuberculosis and leprosy in the patient. Sometimes
autoantibodies like RF and ANA may also be false positive in
leprosy9 but when both RF and anti CCP are negative,
other causes including leprosy should be considered when patient is from
endemic area.13 So not only leprosy patients mimicking
Rheumatoid disease, but also patients with known case of Rheumatoid
disorder may present with signs and symptoms of leprosy during the
course of treatment if there was a latent infection.
Ulnar nerve is the commonest nerve involved in leprosy ranging from
neuritis sensory symptoms to clawing of hand.16Steroid therapy along with MDT is the common medical approach for
treatment of ulnar neuritis. Surgical decompression of nerve is required
in case who failed to respond by 12 weeks of combination therapy with
steroid or in cases with severe ulnar neuritic pain disturbing daily
activities, and with nerve abscess. Dose of steroid varies, commonly
started with 1mg/kg/day gradually tapering weekly and continued for 6-9
months with maintenance dose of 5-10mg/day. In a study by Sajid et al.
Pain recovery was seen in 100% cases, sensory recovery in 60-82% in
6-8 weeks period, and motor improvement (upgrading of MRC score) in
50-80% of cases depending on initial motor power in 24 to 54 weeks
period.
In our case, initially patient presented with polyarthritis and was
treated for seronegative rheumatoid arthritis. Due to the persistence of
symptoms and even worsening, he was noncompliant with medication. After
a few months as he started developing neuropathic symptoms to ulnar
distribution and subsequently ulnar clawing with cutaneous lesions, we
suspected leprosy. With a thorough history, examinations and split skin
smear, he was diagnosed with lepromatous leprosy and treatment started.
This delay in diagnosis was due to misdiagnosis of clinical signs more
towards Rheumatoid and also due to the inability of early detection and
suspicion of leprosy with symptoms timeline. So, it is essential to
recognize the association of arthritis in leprosy, its resemblance with
other inflammatory causes, disease and symptoms progression for early
detection and treatment.