Abstract
A 13-year-old Pacific Island girl presented complaining of fever, joint pain and dry mouth. She was using limes to relieve her dry mouth. On examination, the most striking clinical finding was severe dental erosion and caries. Autoimmune serology confirmed a diagnosis of systemic lupus erythematosus (SLE) with possible Sjögren’s syndrome. The case illustrates the devastating consequence of excessive consumption of acidic citrus juice in sicca syndrome.
Keywords
Case Report
A 13-year-old girl presented with a 2-year history of fever, malaise and joint pains. She was diagnosed with chronic juvenile arthritis in 2008 but was lost to follow-up. She presented again in 2010 with similar complaints but now also with dry mouth and excessive thirst, which was relieved by sucking limes.
On examination, she was febrile and thin with sparse hair. Her left ankle and right wrist were swollen and tender. There was no rash, however she had severe dental erosion with caries (Figure 1), dry lips, and oral mucosa and tongue.
Severe dental erosion and caries 106 × 80mm (72 × 72 DPI).
Initial investigations in 2008 revealed ESR >100 mm/h. Rheumatoid factor and ANA were negative at that time. Investigations in 2010: Hb 9.8 g/dl, WBC 7 × 109/L, lymphocytes 3.1 × 109/L, ANA > 2,560 homogeneous, anti-dsDNA 52 IU/mL, Rheumatoid factor <20 IU/mL and anti Ro and La antibodies negative. Urinalysis was normal, creatinine was 90 Ummol/L.
A diagnosis of systemic lupus erythematosus (SLE) with probable Sjögren’s syndrome was made. She was treated with reducing doses of oral prednisolone and chloroquine. She was encouraged to drink 2 L of water daily to augment saliva production. Dental extraction was performed. She was reviewed recently and remains well on low dose steroids and chloroquine. She is attending school and awaits fitting for dentures when her growth is complete.
Discussion
The key to successful management of SLE is regular review, important when using drugs with serious side effects such as prednisolone and hydroxychloroquine. Chloroquine retinopathy is particularly feared, however the incidence of damage is low when conventional doses (400 mg/day) are used. 1
SLE is two to four times more common in non-white people. Not only is there a difference in susceptibility among ethnic groups but also in expression. 2 SLE is twice as common in Pacific Island and Maori children than European children and tends to be more severe. 3 SLE with Sjögren’s has a better prognosis than SLE alone with relatively less internal organ involvement. 4 This girl had no evidence of renal involvement.
Our diagnosis was made on the basis of her rheumatic complaints and dry mouth, her high titer ANA and positive ds DNA. The latter is 97.4% specific for SLE. ANA is a useful tool in evaluating a case like this, but a positive test is not diagnostic of autoimmune disease and is seen in many non-rheumatic conditions as well as healthy individuals. Consideration of sensitivity and specificity of expensive autoimmune serology is essential. Anti Ro/SSA is seen in 50–60% of cases of primary Sjögren’s and only 10–15% cases of secondary Sjögren’s. 5 The gold standard for diagnosing Sjögren’s syndrome is salivary gland biopsy which unfortunately was not available to us.
In developed countries, excessive ingestion of carbonated soft drinks and bulimia are well known causes of dental erosion. The change to a more Western diet in the Pacific has led to increased dental caries and erosions. In 30 years of practice in developing countries we have never seen such severe dental erosion and caries. Her severe dental erosion was caused by the combination of her dry mouth and the constant use of limes for relief. The optimum oral pH is 4. The pH of lime juice is only 2–2.3 and it is particularly resistant to buffering. The frequent use as opposed to the total intake of lime juice is more significant. The acid environment in her mouth resulting from frequent use of limes combined with the reduction in saliva led to this devastating result. Saliva is a natural buffer with antibacterial properties which protects against dental caries and was also a factor in this case.
Footnotes
Declaration of conflicting interests
None declared.
Funding
This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors.