British Journal of Dermatology (1979) 100, 297.

Pityriasis lichenoides chronica presentingas hypopigmentation

ROGER CLAYTON AND ANDREW WARIN

Department of Dermatology, St Mary's Hospital, and St John's Hospital for Diseases of the Skin, London

Accepted for publication 29 June 1978

SUMMARY

Seven black or dark skinned patients with pityriasis lichenoides; chronica (PLC) are described, whopresented with widespread hypopigmentation. The evidence on which a diagnosis of PLC was madeis presented and the differential diagnosis discussed. The hypopigmentation was noted in somepatients to be especially marked on the proximal parts of the limbs and axillary folds. A diagnosis ofPLC should be considered in all dark skinned patients with a widespread hypopigmented rash.

The polymorphic eruption of pityriasis lichenoides chronica (PLC) is usually characteristic. Theinitial lesion is a small red infiammatory papule which may have a purpuric element. This flattensand develops a characteristic, centrally adherent mica scale which is easily detached to reveal a smooth,shining, red-brown surface. The rate of progression of each lesion varies. Post-inflammatory hypo-pigmentation may occur at sites of healed lesions but is not usually a prominent clinical feature.Lately, we have seen seven patients who presented with an extensive hypopigmented rash. Two ofthese have been described previously (Warin, 1978). We now report these more fully together withfive others.

CASE REPORTS

Case IA 33-year-oId West Indian woman presented with a 4-month history of a pruritic rash. She had had nopreceding illness and was otherwise well. On examination there were large ill-defined areas ofconfluent macular hypopigmentation, with occasional scales, on the limbs and lower trunk, especiallythe buttocks and thighs. A diagnosis of post-inflammatory hypopigmentation following insect biteswas made. Three months later, more extensive hypopigmentation was evident but no other signs.Five months later two small papules with mica scales were seen, each within an area of hypopigmen-tation, on the inner aspect of one thigh. A tentative diagnosis of PLC was made. Biopsy of one of thepapules showed a moderately dense pericapillary lymphocytic infiltrate with overlying epidermal

Reprint requests: Dr R.J. Clayton, Skin Department, St Mary's Hospital, Praed Street, London W2.0007-0963/79/0300-0297 J02.00 © 1979 British Association of Dermatologists

297

298 R.Clayton and A.Warin

spongiosis and at one point, infiltration of the epidermis with inflammatory cells. Since that time,more similar lesions and small dark papules have been seen on the thighs and buttocks. Directimmunofluorescence (IF) of a biopsy of one of these showed IgM deposits in superficial dermal vesselwalls and granular deposits of C3 along the dermal-epidermal junction (D-EJ).

Case 2A 13-year-old Selanese boy presented with a 2-year history of rash which was of sudden onset. Onexamination there was marked macular hypopigmentation mainly of the proximal limbs (Fig. 1)but including the trunk and face. On close examination there were some scales within areas of hypo-pigmentation and occasional dark papules. Histology of one of these showed changes characteristic ofPLC, and IF showed IgM in superficial dermal vessel walls.

FIGURE I. The left thigh of patient 2 showing extensive macular hypopigmentation.

Case 3A 15-year-old West Indian boy born in the United Kingdom presented with a 6-month history ofgeneralized, ill-defined, hypopigmcnted areas especially of the proximal parts of the limbs and aroundthe axillae and sides of the trunk and face. A few mica scaled lesions and inflammatory papules wereseen on a second visit. IF of a biopsy of an inflammatory papule showed C3 in superficial dermal vesselwalls.

Pityriasis Uchenoides chronica 299

Case 4A 9-year-old dark skinned English Caucasian presented with a 4-year history of slowly enlarging paleareas of skin and occasional papules. He had extensive hypopigmentation of the trunk and limbs. Atfollow-up, scaly areas and occasional papules were seen and a diagnosis of eczema was made but 2years later biopsy of a non-specific papule showed perivascular chronic inflammatory cells in thedermis which infiltrated a spongiotic epidermis (Fig. 2). IF showed IgM in superficial dermal vesselwalls.

FIGURE 2. Histology of a clinically non-specific papule from Patient 4 showing characteristicfeatures of PLC(x 180).

CaseA 26-year-old West African woman presented with a slowly spreading, non-irritant hypopigmentedrash mainly of the upper thighs, lower back, upper arms and back of the neck. A diagnosis of pityriasisversicolor or vitiligo was considered but mycology was negative and examination in Wood's light did

300 R.Clayton and A. Warin

not confirm vitiligo. At follow-up small scaly hyperpigmented lesions were seen and biopsy of oneshowed changes characteristic of PLC. Subsequently there has been an extension of the hypo-pigmentation and mica scaled lesions are occasionally seen on the thighs and buttocks.

Case 6

A 7-year-old Indian boy born in the UK had a 6-year history of pale areas of skin, worse in the springand autumn. The rash had disappeared during a 2-month holiday in Pakistan. On examination he hadwidespread small, non-scaly, hypopigmented macules especially of the neck, face and around theaxillae (Figs 3 and 4). Occasional dark inflammatory mica scaled papules were seen. IF was negative.

FIGURE 3. The back of Patient 6 showing hypopigmented macules especially marked around theaxillae.

Case 7

A 5-year old West Indian boy born in the UK presented with a year's history of an extensive symptom-less hypopigmented rash. His body and face were covered with small hypopigmented macules especi-

Pityriasis Uchenoides chronica 301

F iGURE 4. Side of the neck and face of Patient 6 showing confluent hypopigmented areas.

ally marked around the axillae; some trunk and thigh macules showed scahng. At subsequent visitsa few dark papules with mica scales were seen within hypopigmented areas.

DISCUSSION

In black or dark-skinned individuals PLC may present with remarkably widespread hypopigmentation.A clinical diagnosis was made in all oiu: seven patients, sometimes only after repeated and carefulexamination for the characteristic scaly papule. Confirmative histology was obtained in four and posi-tive IF in four.

Both acute and chronic lesions of pityriasis lichenoides (PL) may be followed by hypopigmentation(Rook et al, 1972) but persistent widespread loss of pigment is unusual. In a clinical review of PL(Marks et al, 1972) hypopigmented areas were noted in seven of forty-four patients but it was notremarked upon as being a conspicuous feature. Michelson (1922) drew particular attention toextensive hypopigmentation in PLC pointing out its clinical resemblance to syphilitic leukoderma.He emphasized that a biopsy from the centre of a non-specific hypopigmented area often showedfeatures of the PLC infiltrate.

A diagnosis of eczema, pityriasis versicolor or vitiligo was considered in some of our patients.However, we have noted that there is often a characteristic distribution of the hypopigmented maculesof PLC which mitigates against these. It is more marked on the upper arms and thighs and around theaxillary folds (Fig. 3). Pityriasis versicolor may be excluded by microscopic examination of scrapingsin potassium hydroxide solution. Vitiligo presents as symmetrical areas of well-defined depigmentation.The small lesions of idiopathic guttate hypomelanosis which occtir predominantly on the limbs of

302 R.Clayton and A.Warin

black patients should not be confusing. The loss of pigment in pityriasis alba is not usually so extensiveas that seen in our patients with PLC and favours the upper limbs and face.

A charaaeristic IF pattern has been described on direct IF of fresh lesions of PL (Clayton et al..,1977)—IgW and C3 are seen in superficial dermal vessel walls and along the D-EJ. In four of ourpatients the finding of IgM and/or C3 in these areas supported the clinical and histological findings.

ACKNOWLEDGEMENTS

We thank Dr Etain Cronin, Professor M. Greaves (St John's Hospital for Diseases of the Skin),Dr M. Feiwel and Dr L. Fry (St Mary's Hospital) for permission to study their patients. The Depart-ment of Audio-Visual Communication (St Mary's Hospital) produced the clinical photographs andthe photomicrograph was kindly supplied by the Histopathology Department at St Mary's Hospital.

REFERENCiiS

CLAYTON, R. , HAFFENDEN, G. , DU VIVIER, A., BURTON, J. & MOWBRAY, J. (1977) Pityriasis lichenoides—animmune complex disease. British Journal of Dermatology, 97, 629.

MARKS, R. , BLACK, M.& WILSON-JONES, E . (1972) Pityriasis lichenoides: a reappraisal. British Journal of Dermat-ology, 86, 215.

MICHELSON, H . E . (1922) Leukoderma in pityriasis lichenoides chronica. Archives of Dertnatology, 6, 288.WARIN, A. (1978) Hypochromic variant of pityriasis lichenoides chronica. Clinical and Experimental Dermatology,

3.85-ROOK, A., WILKINSON, D.S. & EBLING, F . J . G . (1972) Textbook of Dermatology, 2nd edn, p. 606. Blackwell

Scientific Publications, Oxford.