the number of patients undergoing chemotherapy grows year by year . despite their efficacy in controlling the cancer , chemotherapy drugs are not inert , and they cause damage to the human body
regarding nail involvement , diverse clinical features can be observed , according to the structure affected and the severity of the damage caused .
the most common chemotherapeutic agents implicated in nail changes are cyclophosphamide , doxorubicin and hydroxyurea [ 2 , 3 ] . in the majority of cases ,
the effects are fully reversible after a few months once the causative agent has been withdrawn [ 2 , 4 ] .
a 25-year - old male patient was admitted to the hospital 's hematology ward with the diagnosis of acute lymphocytic leukemia .
the hyper - cvad regimen delivers a combination of drugs in 2 cycles ( cyclophosphamide , vincristine , doxorubicin and dexamethasone in cycle a , methotrexate and cytarabine in cycle b ) , split into smaller doses and administered at more frequent intervals in order to minimize side effects . during hospitalization , a dermatology assessment was requested .
the dermatological examination showed nail injury characterized by transverse , brown - gray hyperpigmentation affecting the proximal half of the nail plate , with a brown band delimiting the healthy nail plate on all fingers ( fig . 1 , fig
chromonychia induced by chemotherapeutic agents has different forms , the most common being melanonychia [ 2 , 4 , 5 ] . the dark pigmentation in nails can be diffuse , transverse or longitudinal and can coexist with skin and mucosal pigmentation [ 2 , 4 , 6 ] .
it has been suggested that chemotherapy drug regimens influence the incidence of changes that may result from toxicity in the nail matrix , nail bed , periungual tissue and digits vessels [ 2 , 6 ] .
although several chemotherapeutic agents can cause these changes , those most associated with these side effects are cyclophosphamide , doxorubicin and hydroxyurea [ 2 , 3 ] .
cyclophosphamide is an alkylating agent whose main target is the cell cycle ; thus , tissues with high proliferation rates are more susceptible .
alkylating agents form cross - links with dna filaments and prevent dna replication , therefore entailing cytotoxicity .
cyclophosphamide can cause nail changes such as diffuse , black pigmentation , longitudinal striae ranging in color from slate gray to black , and diffuse , dark gray pigmentation located proximally , with overlying transverse , black bands [ 2 , 4 ] .
this drug - induced nail pigmentation starts from the proximal edge of the nail and proceeds towards the distal edge . upon withdrawal of the drug
it takes approximately 46 months [ 2 , 3 ] . in 60% of patients ,
cyclophosphamide is also associated with pigmentation of the oral mucosa and tongue , which also regresses upon withdrawal of the drug [ 2 , 4 ] .
its side effects include skin and nail hyperpigmentation , alopecia , skin rash , pruritus , photosensitivity , urticaria , acral erythema and palmoplantar erythrodysesthesia .
nail changes such as transverse , dark brown bands alternating with white stripes [ 2 , 7 ] and dark brown diffuse pigmentation bands 45 mm wide , which affect two - thirds of the distal portion of the nail , also occur [ 2 , 5 ] .
additionally , doxorubicin can cause subungual keratosis , onycholysis and thickening of the nail plate .
hydroxyurea causes an immediate inhibition of dna synthesis by acting as an inhibitor of ribonucleotide reductase , without interfering in the synthesis of ribonucleic acid or protein .
this pigmentation has a diffuse , dark brown color which may appear as single or double transverse bands [ 2 , 4 ] .
ungual hyperpigmentation induced by chemotherapy is not uncommon , although its occurrence is underestimated and seldom reported , especially in patients with dark skin phototypes , such as our patient , in this case , the drugs most probably implicated are doxorubicin and cyclophosphamide because they produce ungual alterations very similar to the ones seen in our patient ; his chemotherapeutic scheme included both of them .
 chemotherapy drugs can affect the skin and its appendages . 
 several clinical presentations can be observed , depending on the affected structure . 
 the most common dermatological side effect is chromonychia . 
 the main causative agents are : ( 1 ) cyclophosphamide , which can provoke a diffuse , black pigmentation , longitudinal striae and dark grey pigmentation located proximally on the nails ; ( 2 ) doxorubicin , which promotes dark brown bands alternating with white striae and dark brown pigmentation in transverse bands , and ( 3 ) hydroxyurea , which produces a distal , diffuse , dark brown pigmentation . in the majority of cases , 
 the effects are reversible after the suspension of the causative agent for a few months . 
 we report a patient who developed chromonychia while undergoing treatment with cyclophosphamide , vincristine , doxorubicin , dexamethasone , methotrexate and cytarabine for acute lymphocytic leukemia . 