Discussion of the case
A forty-six-year-old female had rashes over her face, scalp, and the extensor surface of her hands. The patient was on treatment for psoriasis for the past 15 years. She had a fever, dry mouth, discoloration of nails, and extensive rashes at presentation. She had a refractory error, but no evidence of dry eyes. Other systems were normal and had no arthritis or muscle pain. Her ANA, anti-ds-DNA, SSA, and Ro- 52 antibodies were positive. Investigations revealed normal blood counts, CRP, elevated SGOT, PT, alkaline phosphatase, GGT, and serum IgE. Urine analysis indicated normal creatinine and other parameters. RNP and Sm were borderline positive. LFT repeated after 1 month was within the normal range.
The flare of psoriasis/failure to respond to the treatment could be one of the possible differential diagnoses. The clinical findings indicate the possibility of psoriasis with overlapping CTD, like Sjogren's syndrome. The other possibilities are allergic dry eczema with overlapping CTD and worsening of discoid or lupus rashes.
Psoriasis and eczema are common in the Indian scenario and the prevalence ranges between 0.3% and 8%.1 The country's prevalence of eczema and atopic dermatitis is between 2.6% and 1.5%.2 Though overlapping of psoriasis with discoid lupus is possible, it is relatively rare.3 The incidence of psoriasis developing as lupus and vice versa reported in a study by Kyrill et al. was around 0.6% and the majority of them had anti-Ro/SSA antibodies.1
The overlap of discoid lupus erythematosus (DLE) with atopic dermatitis is considerably rare and there are very few reported cases.4Â In concurrence with the previous diagnosis, the presence of rashes in extremities, and scalp and limited involvement of the face are more suggestive of psoriasis than allergic diathesis. Â In the present case, elevated IgE is the only indicator of allergic diathesis. But a non-specific elevation of IgE is generally noted in CTD patients, hence it needs to be cautiously interpreted.
No other features are suggestive of SLE, except low C3 and C4. However, the patient fulfills SLICC criteria for diagnosing SLE- chronic DLE. Psoriasis overlapping with DLE could be suspected in the present case, and skin biopsy with immunofluorescence is advocated to conclude the diagnosis. The previous diagnosis of psoriasis by the dermatologist was based on clinical findings and not on skin biopsy.
Final Diagnosis
DLE with psoriasis
Follow-up
The patient was initially treated with HCQ, azathioprine, and a small dose of steroids. She responded well and the rashes/lesions had become minimal. She is currently maintained on azathioprine and HCQ. Her complement levels have become normal and no clinical features of SLE have been reported for one year.
Learning points
- In patients presenting with worsening of psoriasis or eczema lesions and not adequately responding to the treatment, it is necessary to consider a possible overlap.
- The overlap of DLA can occur in patients with psoriasis and skin biopsy is mandatory in such patients.
References
- Dogra S, Yadav S. Psoriasis in India: prevalence and pattern. Indian J Dermatol Venereol Leprol. 2010 Dec;76(6):595–601.
- Pramatarov, Kyrill, and Nikolai Tsankov. Association of Cutaneous Lupus Erythematosus with Other Dermatological Diseases.In: Cutaneous LE, Ed. A. Kuhn, Springer, Berlin, 2005.
- Kumar S, Nayak CS, Padhi T, Rao G, Rao A, Sharma VK, et al. Epidemiological pattern of psoriasis, vitiligo and atopic dermatitis in India: Hospital-based point prevalence. Indian Dermatol Online J. 2014 Nov;5(Suppl 1):S6–8.
- Janjumratsang P, Phainupong D, Chanjanakijskul S, Roongphibulsopit P. Positive direct immunofluorescence and autoantibody profiles in psoriasis patients. J Dermatol. 2008 Aug;35(8):508–13.
- Matsui S, Kitaba S, Itoi S, Kijima A, Murota H, Tani M, et al. A case of disseminated DLE complicated by atopic dermatitis and Sjögren's syndrome: link between hypohidrosis and skin manifestations. Mod Rheumatol. 2011 Feb;21(1):101–5.
Â
