Zinc-Responsive Acral Hyperkeratotic Dermatosis Masquerading as Progressive Symmetrical Erythrokeratoderma in Multidrug-Resistant Tuberculosis Patient

Madam, Dermatological manifestations of zinc deficiency (ZND) may be acute or insidious in nature. Acute deficiency manifests as vesiculobullous eruption with erythema, erosiocrustive lesions involving periorificial areas, hands, and feet, whereas chronic deficiency presents as lichenified and psoriasiform plaques on hands and feet.[1] A 9-year-old-girl presented with complaints of minimally itchy, red, scaly lesions on her hands and feet for the last 3 months. She was a known case of (K/C/O) disseminated tuberculosis (TB) and was on a multidrug-resistant regimen for the last 1 year and tablet phenytoin for seizure for the same duration. There was no history of similar complaints in any family member/history of consanguinity/diarrhea/transient/migratory lesions and fluid/pus-filled lesions. On examination, there were sharply demarcated, dusky red to brownish, hyperkeratotic plaques, with semi-adherent, white scales at the margin and peripheral rim of erythema, present on the dorsae of both hands and feet [Figure 1], volar aspects of wrists and knees. Mucosae and hair examination was normal. Nails showed ragged cuticles. Skin biopsy showed hyperkeratosis, acanthosis, papillomatosis, and chronic perivascular inflammatory infiltrate in the dermis. The absence of necrotic keratinocytes and pigmentary incontinence ruled out the possibility of necrolytic acral erythema [Figure 2]. Hepatitis C serology/liver function test/kidney function test/albumin/alkaline phosphatase were normal. Serum zinc levels could not be done due to financial constraints. The patient was given syrup zinc 50 mg once daily. There was a marked improvement in the form of reduction of erythema, scaling, and hyperkeratosis in 3-week time [Figure 3]. On the basis of history, examination, histopathology, and dramatic response to zinc therapy, we made the final diagnosis of zinc-responsive acral hyperkeratotic dermatosis (ZRAHD).Figure 1: Dusky red to brownish hyperkeratotic plaques with peripheral erythema and semi-adherent, white scales at the marginFigure 2: Histopathological examination (H and E stain, ×10) from the dorsum of hand showing hyperkeratosis, acanthosis, papillomatosis, and chronic perivascular inflammatory infiltrate in the dermisFigure 3: Marked response in the form of reduction of erythema, scaling, and hyperkeratosis after 3-week treatmentZRAHD is a newly described entity. It is characterized by hyperpigmented, psoriasiform plaques, with the occasional rim of erythema, over the dorsae of hands and feet.[2] Classically, histopathology shows hyperkeratosis, focal parakeratosis, acanthosis, pale keratinocytes, and sparse lymphohistiocytic infiltrate in the upper dermis.[2] Serum zinc levels have been found to be normal in most of the previously reported patients so it does not have much role in diagnosis. ZRAHD may be associated with various diseases [Table 1]. Most of ZRAHD patients have renal dysfunction which can very well explain this association as chronic renal disorders may be associated with ZND.[2]Table 1: Associated diseases with zinc-responsive acral hyperkeratotic dermatosisStudies have shown ZND in TB patients. However, there is no case report to date on ZRAHD in TB. Our patient was a K/C/O TB. The proposed mechanism of ZND in TB patients is the utilization of zinc by Mycobacteriumtuberculosis for growth, redistribution of zinc from plasma to liver for acute phase reactants synthesis, and reduced zinc carrier protein production.[4] Another mechanism in our patient could be phenytoin intake which can chelate zinc and may lead to its deficiency.[5] In our patient mechanism of ZND was the presence of TB and phenytoin intake. However, in previously reported cases, no such associations have been described. Another interesting point that we want to highlight is the resemblance of this entity to progressive symmetrical erythrokeratoderma. We also want to emphasize that because of the association of most of the previously reported cases with chronic renal disease this entity should be suspected in these patients, having hyperkeratotic skin lesions on acral areas. Declaration of consent The authors certify that they have obtained all appropriate consent forms, duly signed by the parent(s)/guardian(s) of the patient. In the form, the parent(s)/guardian(s) has/have given his/her/their consent for the images and other clinical information of their child to be reported in the journal. The parents understand that the names and initials of their child/children will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.