|Year : 1994 | Volume
| Issue : 2 | Page : 105-107
T Sangeeta Amladi, Mala Kohli
T Sangeeta Amladi
Source of Support: None, Conflict of Interest: None
A rare case of Hartnup disease is presented - the patient being an 11 year old school girl suffering from a typically pellagroid rash in the absence of any other signs of malnutrition. No accompanying neurological or psychiatric features are seen, but electro-encephalography revealed abnormal baseline activity. Investigations and management are detailed and the literature on Hartnup disease reviewed.
Keywords: Pellagroid rash, Aminoaciduria, Hartnup disease
|How to cite this article:|
Amladi T S, Kohli M. Hartnup disease. Indian J Dermatol Venereol Leprol 1994;60:105-7
| Introduction|| |
Hartnup disease is a rare autosomal recessive inborn error of neutral amino-acid transport. It was first reported by Baron et al in 1956  and so named after the surname of the initial family identified. Since then only 53 cases have been diagnosed all over the world, of which 4 have been from India. 
Of all the amino-acids affected, it is the abnormal membrane transport of the essential amino-acid, tryptophan, which results in a secondary niacin deficiency; this gives rise to the pellagra-like manifestations, both cutaneous and neuropsychiatric.
| Case Report|| |
A 11-year-old schoolgirl presented with red, scaly, mildly itchy pellagrous lesions on exposed parts of the face and extremities of 4 months duration. There was no history of blistering, mucosal lesions, sun sensitivity or drug intake. In the last 7 days, she had also developed high grade intermittent fever without chills.
She had been a full-term normal delivery born of a non-consanguineous marriage. Her milestones had been normal and she was scholastically bright, well behaved and well oriented. There was no abnormal gait or movement, and she was not irritable, moody or apathic.
The patient was a vegetarian eating a balanced diet not containing maize. Over the past 4 years, she had a few transient episodes of similar skin rashes, but restricted to both forearms She had also suffered thrice from urinary tract infection and once from hepatitis.
No family member was similarly affected. For the present complaint, she had been treated with systemic steroids and other medications with no benefit.
On examination, the patient was febrile but well oriented and of adequate built and nutrition. The cutaneous lesions were classically pellagroid, being sharply demarcated erythematous plaques with peripheral scaling, crusting and hyperpigmentation. They were located on the face, neck, extensor aspects of both forearms from hands to elbows and on both legs extending from feet to knees. The tongue was swollen and beefy red, and the alae nasi and lips showed adherent crusts. The vulva and groins were macerated. No systemic abnormality was detected.
This uncommon presentation of a recurrent pellagroid rash in a young girl with no obvious nutritional deficiency indicated a search for disorders of amino-acid metabolism, viz. Hartnup disease and congenital tryptophanuria. On investigation, routine blood, urine and stool studies, X-ray chest and ECG were all normal except for evidence of a urinary tract infection.
A urinary amino-acidogram, performed first by high pressure liquid chromatography, and later by paper chromatography, revealed a constant generalised amino-aciduria of the neutral amino-acid group. T he amino-acids excreted were glutamine, serine, alanine, tyrosine, valine, methionine, phenylalanine, leucine, isoleucine and tryptophan, conforming to the Hartnup pattern. Urinary indoles, initially negative, tested positive on increasing the sensitivity of the test, thus reieterating the diagnosis. Plasma tryptophan levels were markedly low.
Porphyrin studies and protein electrophoresis were negative. EEG showed a pattern of baseline activity suggestive of a seizure disorder. A lesional skin biopsy revealed subacute eczematous changes compatible with a pellagroid rash.
The patient was treated with oral Nicotinamide, 300 mg per day and Pyridoxine, 30 mg per day. She improved dramatically; all the cutaneous lesions healed leaving behind post-inflammatory hyperpigmentation. She has in addition. been advised a balanced diet and photoprotection.
Her urine analysis done at regular intervals continues to show the amino-aciduria. Urine samples of her family members tested similarly however have detected no abnormality.
| Comments|| |
The point in favour of the diagnosis of Hartnup disease in our patient are the pellagroid rash, constant generalised aminoaciduria of the neutral (mono-amino monocarboxylic) group, increased urinary excretion of indoles and response to nicotinamide therapy.
Hartnup disease typically presents between 3-9 years of age, and most often with cutaneous manifestations. Neurological signs, the commonest of which is cerebellar ataxia, appear later, may or may not accompany the rash and are usually transient and completely reversible. Psychiatric abnormalities are less common and may range from minimal emotional disturbances to depression, delusions and suicidal tendencies. The disease follows a course of remissions and relapses, may improve with age, and is noted to commonly exacerbate in spring or early summer with sulfa therapy, or following febrile illnesses,  as witnessed in our patient.
The primary defect is monogenic and results in impairment of membrane transport mechanisms selectively for amino-acids of the mono-amino mono-carboxylic (neutral) group;  this impairment can be localised to the intestine or the kidney, or involve both together;  pure intestinal defect results in marked growth and developmental delay : pure renal, in urinary findings only. It is the combined defect in both organs that gives rise to cutaneous, systemic and urinary manifestations classical of Hartnup disease and the present case fits into this category.
The clinical polymorphism soen in this disease may be due to difference in severity of the primary defect, especially in the intestine, in different patients; thus even minor periods of nutritional imbalance, as seen in diarrhoea or acute febrile illnesses, may set off a relapse. Biochemical changes however remain constant in all patients regardless of clinical features or treatment and in fact, routine urine screening has detected many asymptomatic cases.
In the present case, therefore, absence of neurological and psychiatric manifestations does not in any way contradict the diagnosis of Hartnup disease; the abnormal EEG pattern noted may be an indicator of future such developments.
| Acknowledgements|| |
We are grateful to Dr. (Mrs) N D Patil, Department of Biochemistry, L T M Medical College & General Hospital, and the Paediatric Research Laboratory, K E M Hospital for assistance in the patient's investigations.
| References|| |
|1.||Baron D N, Dent C E, Harris H, Hart E W, Jepson J B. Hereditary pellagra-like skin rash with temporary cerebellar ataxia. Constant renal amino-aciduria and other bizarre biochemical features. Lancet 1956; 2 : 421-8. |
|2.||Verma I S. Inborn errors of metabolism and metabolic disorders. In : Textbook of Pediatrics (Udani PM, ed), Vol 2. Jaypee Brothers, 1991; 2362. |
|3.||Halvorsen K, Halvorsen S. Hartnup disease. Pediatrics 1963; 31 : 29-38. |
|4.||Scriver C R. Hartnup disease : a genetic modification of intestinal and renal transport of certain neutral alpha-amino acids. N Engl J Med 1965; 273 : 530-2. |
|5.||Matthews D M. Experimental approach in chemical pathology. Br Med J 1971; iii : 659-64. |
|6.||Rezvani I, Auerbach V H. Metabolic diseases. In : Nelson, Textbook of Paediatrics. (Behrman RE, ed), 14th edn. W B Saunders Co, 1992; 315-6. |