No Hypopigmented Lesion, No Nerve Thickening, But Its Leprosy!

Ref.:   No Hypopigmented Lesion, No Nerve Thickening, But Its Leprosy!
From: G Warren, Sydney, Australia

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Dear Dr Noto.,

Thank you very much to Ms Nathalie Koumans for her message [LML may 22nd, 2012].  I was very pleased to open the new list posted from Infoleps of leprosy articles, available on line.  This article was of particular interest.
“No Hypopigmented Lesion, No Nerve Thickening, But Its Leprosy!”
Ashish Singh, S Ambujam, and N S Pradeep Kumar
Indian J Dermatol. 2012 Jan-Feb; 57(1): 73–74.
doi:  10.4103/0019-5154.92689

This is a very timely article based on the general acceptance of the W.H.O. definition that a patient with leprosy must have a skin patch with a definite loss of sensation.  The writers describe a very common problem in many countries where the pinkish ENL spot may become and go and may ulcerate and become infected and may even be uncomfortable but, the quickest way of checking the diagnosis of leprosy is often by a slit skin smear.  Yes, I am afraid that good reliable technicians able to do a good smear are becoming more rare, but It is important that general dermatologists and physicians need to remember that early Lepromatous leprosy may have very vague lesions or fluctuating ones (as ENL does) that have no loss of pain or obvious abnormality in touch.

Yes, “what we do not think about we will never diagnose” and in endemic countries we need to still be aware that  leprosy is present but, we will not diagnose it if we do not look for it.

Having worked in eastern Asia for many years I am very familiar with this early LL type of leprosy in which there are no obvious lesions for many years though if one palpates carefully one realises that there is some infiltration.  If the positive diagnosis is made at that early stage then there is often no real problems managing reaction and recovery does occur relatively rapidly without deformity or disability.  

I vividly remember one middle aged Chinese woman whose face was generally infiltrated but, she had no obvious edges and no definite lesion.   However on careful examination one could feel the infiltration and appreciate that the upper lip was not as infiltrated as the rest of the face.  The diagnosis was made because a nodule on her arm was biopsied!   In follow up we found slit skin smears with bacteriological index (BI) of 3+ and 4+ in every site where we examined even if there was no sign of a definite lesion.

This is a timely reminder and one wonders how many of these patients are treated for some other disease or just not treated till the leprosy is definite and that often means that deformity or disability will result.  Also the patients most likely to have this type of lesion are those at lepromatous end of spectrum and so most likely to transmit the disease to their contacts; even if they are not manifesting obvious lesions.

May we really look for these cases and early treatment will help to keep the numbers of new cases down.

Yours sincerely,

Grace Warren
Previously Med Superintendent of  Hong Kong leprosarium 1959-1975. 
Adviser in Leprosy  and Reconstructive Surgery for the Leprosy Mission Asia 1975-1995.